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duktape/src-input/duk_bi_buffer.c

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/*
* Khronos/ES6 TypedArray and Node.js Buffer built-ins
*/
#include "duk_internal.h"
/*
* Helpers for buffer handling, enabled with DUK_USE_BUFFEROBJECT_SUPPORT.
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
/* Map class number (minus DUK_HOBJECT_CLASS_BUFOBJ_MIN) to a bidx for the
* default internal prototype.
*/
static const duk_uint8_t duk__buffer_proto_from_classnum[] = {
DUK_BIDX_ARRAYBUFFER_PROTOTYPE,
DUK_BIDX_DATAVIEW_PROTOTYPE,
DUK_BIDX_INT8ARRAY_PROTOTYPE,
DUK_BIDX_UINT8ARRAY_PROTOTYPE,
DUK_BIDX_UINT8CLAMPEDARRAY_PROTOTYPE,
DUK_BIDX_INT16ARRAY_PROTOTYPE,
DUK_BIDX_UINT16ARRAY_PROTOTYPE,
DUK_BIDX_INT32ARRAY_PROTOTYPE,
DUK_BIDX_UINT32ARRAY_PROTOTYPE,
DUK_BIDX_FLOAT32ARRAY_PROTOTYPE,
DUK_BIDX_FLOAT64ARRAY_PROTOTYPE
};
/* Map DUK_HBUFOBJ_ELEM_xxx to duk_hobject class number.
* Sync with duk_hbufobj.h and duk_hobject.h.
*/
static const duk_uint8_t duk__buffer_class_from_elemtype[9] = {
DUK_HOBJECT_CLASS_UINT8ARRAY,
DUK_HOBJECT_CLASS_UINT8CLAMPEDARRAY,
DUK_HOBJECT_CLASS_INT8ARRAY,
DUK_HOBJECT_CLASS_UINT16ARRAY,
DUK_HOBJECT_CLASS_INT16ARRAY,
DUK_HOBJECT_CLASS_UINT32ARRAY,
DUK_HOBJECT_CLASS_INT32ARRAY,
DUK_HOBJECT_CLASS_FLOAT32ARRAY,
DUK_HOBJECT_CLASS_FLOAT64ARRAY
};
/* Map DUK_HBUFOBJ_ELEM_xxx to prototype object built-in index.
* Sync with duk_hbufobj.h.
*/
static const duk_uint8_t duk__buffer_proto_from_elemtype[9] = {
DUK_BIDX_UINT8ARRAY_PROTOTYPE,
DUK_BIDX_UINT8CLAMPEDARRAY_PROTOTYPE,
DUK_BIDX_INT8ARRAY_PROTOTYPE,
DUK_BIDX_UINT16ARRAY_PROTOTYPE,
DUK_BIDX_INT16ARRAY_PROTOTYPE,
DUK_BIDX_UINT32ARRAY_PROTOTYPE,
DUK_BIDX_INT32ARRAY_PROTOTYPE,
DUK_BIDX_FLOAT32ARRAY_PROTOTYPE,
DUK_BIDX_FLOAT64ARRAY_PROTOTYPE
};
/* Map DUK__FLD_xxx to byte size. */
static const duk_uint8_t duk__buffer_nbytes_from_fldtype[6] = {
1, /* DUK__FLD_8BIT */
2, /* DUK__FLD_16BIT */
4, /* DUK__FLD_32BIT */
4, /* DUK__FLD_FLOAT */
8, /* DUK__FLD_DOUBLE */
0 /* DUK__FLD_VARINT; not relevant here */
};
/* Bitfield for each DUK_HBUFOBJ_ELEM_xxx indicating which element types
* are compatible with a blind byte copy for the TypedArray set() method (also
* used for TypedArray constructor). Array index is target buffer elem type,
* bitfield indicates compatible source types. The types must have same byte
* size and they must be coercion compatible.
*/
#if !defined(DUK_USE_PREFER_SIZE)
static duk_uint16_t duk__buffer_elemtype_copy_compatible[9] = {
/* xxx -> DUK_HBUFOBJ_ELEM_UINT8 */
(1U << DUK_HBUFOBJ_ELEM_UINT8) |
(1U << DUK_HBUFOBJ_ELEM_UINT8CLAMPED) |
(1U << DUK_HBUFOBJ_ELEM_INT8),
/* xxx -> DUK_HBUFOBJ_ELEM_UINT8CLAMPED
* Note: INT8 is -not- copy compatible, e.g. -1 would coerce to 0x00.
*/
(1U << DUK_HBUFOBJ_ELEM_UINT8) |
(1U << DUK_HBUFOBJ_ELEM_UINT8CLAMPED),
/* xxx -> DUK_HBUFOBJ_ELEM_INT8 */
(1U << DUK_HBUFOBJ_ELEM_UINT8) |
(1U << DUK_HBUFOBJ_ELEM_UINT8CLAMPED) |
(1U << DUK_HBUFOBJ_ELEM_INT8),
/* xxx -> DUK_HBUFOBJ_ELEM_UINT16 */
(1U << DUK_HBUFOBJ_ELEM_UINT16) |
(1U << DUK_HBUFOBJ_ELEM_INT16),
/* xxx -> DUK_HBUFOBJ_ELEM_INT16 */
(1U << DUK_HBUFOBJ_ELEM_UINT16) |
(1U << DUK_HBUFOBJ_ELEM_INT16),
/* xxx -> DUK_HBUFOBJ_ELEM_UINT32 */
(1U << DUK_HBUFOBJ_ELEM_UINT32) |
(1U << DUK_HBUFOBJ_ELEM_INT32),
/* xxx -> DUK_HBUFOBJ_ELEM_INT32 */
(1U << DUK_HBUFOBJ_ELEM_UINT32) |
(1U << DUK_HBUFOBJ_ELEM_INT32),
/* xxx -> DUK_HBUFOBJ_ELEM_FLOAT32 */
(1U << DUK_HBUFOBJ_ELEM_FLOAT32),
/* xxx -> DUK_HBUFOBJ_ELEM_FLOAT64 */
(1U << DUK_HBUFOBJ_ELEM_FLOAT64)
};
#endif /* !DUK_USE_PREFER_SIZE */
DUK_LOCAL duk_hbufobj *duk__hbufobj_promote_this(duk_context *ctx) {
duk_hthread *thr;
duk_tval *tv_dst;
duk_hbufobj *res;
thr = (duk_hthread *) ctx;
duk_push_this(ctx);
DUK_ASSERT(duk_is_buffer(ctx, -1));
res = (duk_hbufobj *) duk_to_hobject(ctx, -1);
DUK_ASSERT_HBUFOBJ_VALID(res);
DUK_DD(DUK_DDPRINT("promoted 'this' automatically to an ArrayBuffer: %!iT", duk_get_tval(ctx, -1)));
tv_dst = duk_get_borrowed_this_tval(ctx);
DUK_TVAL_SET_OBJECT_UPDREF(thr, tv_dst, (duk_hobject *) res);
duk_pop(ctx);
return res;
}
/* Shared helper. */
DUK_LOCAL duk_hbufobj *duk__getrequire_bufobj_this(duk_context *ctx, duk_bool_t throw_flag) {
duk_hthread *thr;
duk_tval *tv;
duk_hbufobj *h_this;
DUK_ASSERT(ctx != NULL);
thr = (duk_hthread *) ctx;
tv = duk_get_borrowed_this_tval(ctx);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_OBJECT(tv)) {
h_this = (duk_hbufobj *) DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h_this != NULL);
if (DUK_HOBJECT_IS_BUFOBJ((duk_hobject *) h_this)) {
DUK_ASSERT_HBUFOBJ_VALID(h_this);
return h_this;
}
} else if (DUK_TVAL_IS_BUFFER(tv)) {
/* Promote a plain buffer to an ArrayBuffer. This is very
* inefficient but allows plain buffer to be used wherever
* ArrayBuffer is used with very small cost; hot path functions
* like index read/write calls should provide direct buffer
* support to avoid promotion.
*/
/* XXX: make this conditional to a flag if call sites need it? */
h_this = duk__hbufobj_promote_this(ctx);
DUK_ASSERT(h_this != NULL);
DUK_ASSERT_HBUFOBJ_VALID(h_this);
return h_this;
}
if (throw_flag) {
DUK_ERROR_TYPE(thr, DUK_STR_NOT_BUFFER);
}
return NULL;
}
/* Check that 'this' is a duk_hbufobj and return a pointer to it. */
DUK_LOCAL duk_hbufobj *duk__get_bufobj_this(duk_context *ctx) {
return duk__getrequire_bufobj_this(ctx, 0);
}
/* Check that 'this' is a duk_hbufobj and return a pointer to it
* (NULL if not).
*/
DUK_LOCAL duk_hbufobj *duk__require_bufobj_this(duk_context *ctx) {
return duk__getrequire_bufobj_this(ctx, 1);
}
/* Check that value is a duk_hbufobj and return a pointer to it. */
DUK_LOCAL duk_hbufobj *duk__require_bufobj_value(duk_context *ctx, duk_idx_t idx) {
duk_hthread *thr;
duk_tval *tv;
duk_hbufobj *h_obj;
thr = (duk_hthread *) ctx;
/* Don't accept relative indices now. */
DUK_ASSERT(idx >= 0);
tv = duk_require_tval(ctx, idx);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_OBJECT(tv)) {
h_obj = (duk_hbufobj *) DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h_obj != NULL);
if (DUK_HOBJECT_IS_BUFOBJ((duk_hobject *) h_obj)) {
DUK_ASSERT_HBUFOBJ_VALID(h_obj);
return h_obj;
}
} else if (DUK_TVAL_IS_BUFFER(tv)) {
h_obj = (duk_hbufobj *) duk_to_hobject(ctx, idx);
DUK_ASSERT(h_obj != NULL);
DUK_ASSERT_HBUFOBJ_VALID(h_obj);
return h_obj;
}
DUK_ERROR_TYPE(thr, DUK_STR_NOT_BUFFER);
return NULL; /* not reachable */
}
DUK_LOCAL void duk__set_bufobj_buffer(duk_context *ctx, duk_hbufobj *h_bufobj, duk_hbuffer *h_val) {
duk_hthread *thr;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
DUK_ASSERT(ctx != NULL);
DUK_ASSERT(h_bufobj != NULL);
DUK_ASSERT(h_bufobj->buf == NULL); /* no need to decref */
DUK_ASSERT(h_val != NULL);
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
h_bufobj->buf = h_val;
DUK_HBUFFER_INCREF(thr, h_val);
h_bufobj->length = (duk_uint_t) DUK_HBUFFER_GET_SIZE(h_val);
DUK_ASSERT(h_bufobj->shift == 0);
DUK_ASSERT(h_bufobj->elem_type == DUK_HBUFOBJ_ELEM_UINT8);
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
}
DUK_LOCAL duk_hbufobj *duk__push_arraybuffer_with_length(duk_context *ctx, duk_uint_t len) {
duk_hbuffer *h_val;
duk_hbufobj *h_bufobj;
(void) duk_push_fixed_buffer(ctx, (duk_size_t) len);
h_val = (duk_hbuffer *) duk_known_hbuffer(ctx, -1);
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_ARRAYBUFFER),
DUK_BIDX_ARRAYBUFFER_PROTOTYPE);
DUK_ASSERT(h_bufobj != NULL);
duk__set_bufobj_buffer(ctx, h_bufobj, h_val);
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
return h_bufobj;
}
/* Shared offset/length coercion helper. */
DUK_LOCAL void duk__resolve_offset_opt_length(duk_context *ctx,
duk_hbufobj *h_bufarg,
duk_idx_t idx_offset,
duk_idx_t idx_length,
duk_uint_t *out_offset,
duk_uint_t *out_length,
duk_bool_t throw_flag) {
duk_hthread *thr;
duk_int_t offset_signed;
duk_int_t length_signed;
duk_uint_t offset;
duk_uint_t length;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
offset_signed = duk_to_int(ctx, idx_offset);
if (offset_signed < 0) {
goto fail_range;
}
offset = (duk_uint_t) offset_signed;
if (offset > h_bufarg->length) {
goto fail_range;
}
DUK_ASSERT_DISABLE(offset >= 0); /* unsigned */
DUK_ASSERT(offset <= h_bufarg->length);
if (duk_is_undefined(ctx, idx_length)) {
DUK_ASSERT(h_bufarg->length >= offset);
length = h_bufarg->length - offset; /* >= 0 */
} else {
length_signed = duk_to_int(ctx, idx_length);
if (length_signed < 0) {
goto fail_range;
}
length = (duk_uint_t) length_signed;
DUK_ASSERT(h_bufarg->length >= offset);
if (length > h_bufarg->length - offset) {
/* Unlike for negative arguments, some call sites
* want length to be clamped if it's positive.
*/
if (throw_flag) {
goto fail_range;
} else {
length = h_bufarg->length - offset;
}
}
}
DUK_ASSERT_DISABLE(length >= 0); /* unsigned */
DUK_ASSERT(offset + length <= h_bufarg->length);
*out_offset = offset;
*out_length = length;
return;
fail_range:
DUK_ERROR_RANGE(thr, DUK_STR_INVALID_ARGS);
}
/* Shared lenient buffer length clamping helper. No negative indices, no
* element/byte shifting.
*/
DUK_LOCAL void duk__clamp_startend_nonegidx_noshift(duk_context *ctx,
duk_int_t buffer_length,
duk_idx_t idx_start,
duk_idx_t idx_end,
duk_int_t *out_start_offset,
duk_int_t *out_end_offset) {
duk_int_t start_offset;
duk_int_t end_offset;
DUK_ASSERT(out_start_offset != NULL);
DUK_ASSERT(out_end_offset != NULL);
/* undefined coerces to zero which is correct */
start_offset = duk_to_int_clamped(ctx, idx_start, 0, buffer_length);
if (duk_is_undefined(ctx, idx_end)) {
end_offset = buffer_length;
} else {
end_offset = duk_to_int_clamped(ctx, idx_end, start_offset, buffer_length);
}
DUK_ASSERT(start_offset >= 0);
DUK_ASSERT(start_offset <= buffer_length);
DUK_ASSERT(end_offset >= 0);
DUK_ASSERT(end_offset <= buffer_length);
DUK_ASSERT(start_offset <= end_offset);
*out_start_offset = start_offset;
*out_end_offset = end_offset;
}
/* Shared lenient buffer length clamping helper. Indices are treated as
* element indices (though output values are byte offsets) which only
* really matters for TypedArray views as other buffer object have a zero
* shift. Negative indices are counted from end of input slice; crossed
* indices are clamped to zero length; and final indices are clamped
* against input slice. Used for e.g. ArrayBuffer slice().
*/
DUK_LOCAL void duk__clamp_startend_negidx_shifted(duk_context *ctx,
duk_int_t buffer_length,
duk_uint8_t buffer_shift,
duk_idx_t idx_start,
duk_idx_t idx_end,
duk_int_t *out_start_offset,
duk_int_t *out_end_offset) {
duk_int_t start_offset;
duk_int_t end_offset;
DUK_ASSERT(out_start_offset != NULL);
DUK_ASSERT(out_end_offset != NULL);
buffer_length >>= buffer_shift; /* as (full) elements */
/* Resolve start/end offset as element indices first; arguments
* at idx_start/idx_end are element offsets. Working with element
* indices first also avoids potential for wrapping.
*/
start_offset = duk_to_int(ctx, idx_start);
if (start_offset < 0) {
start_offset = buffer_length + start_offset;
}
if (duk_is_undefined(ctx, idx_end)) {
end_offset = buffer_length;
} else {
end_offset = duk_to_int(ctx, idx_end);
if (end_offset < 0) {
end_offset = buffer_length + end_offset;
}
}
/* Note: start_offset/end_offset can still be < 0 here. */
if (start_offset < 0) {
start_offset = 0;
} else if (start_offset > buffer_length) {
start_offset = buffer_length;
}
if (end_offset < start_offset) {
end_offset = start_offset;
} else if (end_offset > buffer_length) {
end_offset = buffer_length;
}
DUK_ASSERT(start_offset >= 0);
DUK_ASSERT(start_offset <= buffer_length);
DUK_ASSERT(end_offset >= 0);
DUK_ASSERT(end_offset <= buffer_length);
DUK_ASSERT(start_offset <= end_offset);
/* Convert indices to byte offsets. */
start_offset <<= buffer_shift;
end_offset <<= buffer_shift;
*out_start_offset = start_offset;
*out_end_offset = end_offset;
}
DUK_INTERNAL void duk_hbufobj_promote_plain(duk_context *ctx, duk_idx_t idx) {
if (duk_is_buffer(ctx, idx)) {
duk_to_object(ctx, idx);
}
}
DUK_INTERNAL void duk_hbufobj_push_arraybuffer_from_plain(duk_hthread *thr, duk_hbuffer *h_buf) {
duk_context *ctx;
duk_hbufobj *h_bufobj;
ctx = (duk_context *) thr;
/* Push ArrayBuffer which will share the same underlying buffer. */
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_ARRAYBUFFER),
DUK_BIDX_ARRAYBUFFER_PROTOTYPE);
DUK_ASSERT(h_bufobj != NULL);
duk__set_bufobj_buffer(ctx, h_bufobj, h_buf);
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
}
/* Indexed read helper for buffer objects, also called from outside this file. */
DUK_INTERNAL void duk_hbufobj_push_validated_read(duk_context *ctx, duk_hbufobj *h_bufobj, duk_uint8_t *p, duk_small_uint_t elem_size) {
duk_double_union du;
DUK_MEMCPY((void *) du.uc, (const void *) p, (size_t) elem_size);
switch (h_bufobj->elem_type) {
case DUK_HBUFOBJ_ELEM_UINT8:
case DUK_HBUFOBJ_ELEM_UINT8CLAMPED:
duk_push_uint(ctx, (duk_uint_t) du.uc[0]);
break;
case DUK_HBUFOBJ_ELEM_INT8:
duk_push_int(ctx, (duk_int_t) (duk_int8_t) du.uc[0]);
break;
case DUK_HBUFOBJ_ELEM_UINT16:
duk_push_uint(ctx, (duk_uint_t) du.us[0]);
break;
case DUK_HBUFOBJ_ELEM_INT16:
duk_push_int(ctx, (duk_int_t) (duk_int16_t) du.us[0]);
break;
case DUK_HBUFOBJ_ELEM_UINT32:
duk_push_uint(ctx, (duk_uint_t) du.ui[0]);
break;
case DUK_HBUFOBJ_ELEM_INT32:
duk_push_int(ctx, (duk_int_t) (duk_int32_t) du.ui[0]);
break;
case DUK_HBUFOBJ_ELEM_FLOAT32:
duk_push_number(ctx, (duk_double_t) du.f[0]);
break;
case DUK_HBUFOBJ_ELEM_FLOAT64:
duk_push_number(ctx, (duk_double_t) du.d);
break;
default:
DUK_UNREACHABLE();
}
}
/* Indexed write helper for buffer objects, also called from outside this file. */
DUK_INTERNAL void duk_hbufobj_validated_write(duk_context *ctx, duk_hbufobj *h_bufobj, duk_uint8_t *p, duk_small_uint_t elem_size) {
duk_double_union du;
/* NOTE! Caller must ensure that any side effects from the
* coercions below are safe. If that cannot be guaranteed
* (which is normally the case), caller must coerce the
* argument using duk_to_number() before any pointer
* validations; the result of duk_to_number() always coerces
* without side effects here.
*/
switch (h_bufobj->elem_type) {
case DUK_HBUFOBJ_ELEM_UINT8:
du.uc[0] = (duk_uint8_t) duk_to_uint32(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_UINT8CLAMPED:
du.uc[0] = (duk_uint8_t) duk_to_uint8clamped(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_INT8:
du.uc[0] = (duk_uint8_t) duk_to_int32(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_UINT16:
du.us[0] = (duk_uint16_t) duk_to_uint32(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_INT16:
du.us[0] = (duk_uint16_t) duk_to_int32(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_UINT32:
du.ui[0] = (duk_uint32_t) duk_to_uint32(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_INT32:
du.ui[0] = (duk_uint32_t) duk_to_int32(ctx, -1);
break;
case DUK_HBUFOBJ_ELEM_FLOAT32:
du.f[0] = (duk_float_t) duk_to_number_m1(ctx);
break;
case DUK_HBUFOBJ_ELEM_FLOAT64:
du.d = (duk_double_t) duk_to_number_m1(ctx);
break;
default:
DUK_UNREACHABLE();
}
DUK_MEMCPY((void *) p, (const void *) du.uc, (size_t) elem_size);
}
/* Helper to create a fixed buffer from argument value at index 0.
* Node.js and allocPlain() compatible.
*/
DUK_LOCAL duk_hbuffer *duk__hbufobj_fixed_from_argvalue(duk_context *ctx) {
duk_int_t len;
duk_int_t i;
duk_size_t buf_size;
switch (duk_get_type(ctx, 0)) {
case DUK_TYPE_NUMBER: {
len = duk_to_int_clamped(ctx, 0, 0, DUK_INT_MAX);
(void) duk_push_fixed_buffer(ctx, (duk_size_t) len);
break;
}
case DUK_TYPE_BUFFER: /* Treat like ArrayBuffer. */
case DUK_TYPE_OBJECT: {
duk_uint8_t *buf;
/* XXX: to be revised, https://nodejs.org/api/buffer.html#buffer_buffer_from_buffer_alloc_and_buffer_allocunsafe
* "Passing an ArrayBuffer returns a Buffer that shares allocated memory with the given ArrayBuffer."
*/
/* XXX: fast path for typed arrays and other buffer objects? */
(void) duk_get_prop_string(ctx, 0, "length");
len = duk_to_int_clamped(ctx, -1, 0, DUK_INT_MAX);
duk_pop(ctx);
buf = (duk_uint8_t *) duk_push_fixed_buffer_nozero(ctx, (duk_size_t) len); /* no zeroing, all indices get initialized */
for (i = 0; i < len; i++) {
/* XXX: fast path for array or buffer arguments? */
duk_get_prop_index(ctx, 0, (duk_uarridx_t) i);
buf[i] = (duk_uint8_t) (duk_to_uint32(ctx, -1) & 0xffU);
duk_pop(ctx);
}
break;
}
case DUK_TYPE_STRING: {
/* ignore encoding for now */
duk_require_hstring_notsymbol(ctx, 0);
duk_dup_0(ctx);
(void) duk_to_buffer(ctx, -1, &buf_size);
break;
}
default:
DUK_ERROR_TYPE_INVALID_ARGS((duk_hthread *) ctx);
}
DUK_ASSERT(duk_is_buffer(ctx, -1));
return duk_known_hbuffer(ctx, -1);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer constructor
*
* Node.js Buffers are just Uint8Arrays with internal prototype set to
* Buffer.prototype so they're handled otherwise the same as Uint8Array.
* However, the constructor arguments are very different so a separate
* constructor entry point is used.
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_constructor(duk_context *ctx) {
duk_hbuffer *h_buf;
h_buf = duk__hbufobj_fixed_from_argvalue(ctx);
DUK_ASSERT(h_buf != NULL);
duk_push_buffer_object(ctx,
-1,
0,
DUK_HBUFFER_FIXED_GET_SIZE((duk_hbuffer_fixed *) h_buf),
DUK_BUFOBJ_UINT8ARRAY);
duk_push_hobject_bidx(ctx, DUK_BIDX_NODEJS_BUFFER_PROTOTYPE);
duk_set_prototype(ctx, -2);
/* XXX: a more direct implementation */
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* ArrayBuffer, DataView, and TypedArray constructors
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_arraybuffer_constructor(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_bufobj;
duk_hbuffer *h_val;
duk_int_t len;
DUK_ASSERT_CTX_VALID(ctx);
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
duk_require_constructor_call(ctx);
len = duk_to_int(ctx, 0);
if (len < 0) {
goto fail_length;
}
(void) duk_push_fixed_buffer(ctx, (duk_size_t) len);
h_val = (duk_hbuffer *) duk_known_hbuffer(ctx, -1);
#if !defined(DUK_USE_ZERO_BUFFER_DATA)
/* Khronos/ES6 requires zeroing even when DUK_USE_ZERO_BUFFER_DATA
* is not set.
*/
DUK_ASSERT(!DUK_HBUFFER_HAS_DYNAMIC((duk_hbuffer *) h_val));
DUK_MEMZERO((void *) DUK_HBUFFER_FIXED_GET_DATA_PTR(thr->heap, h_val), (duk_size_t) len);
#endif
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_ARRAYBUFFER),
DUK_BIDX_ARRAYBUFFER_PROTOTYPE);
DUK_ASSERT(h_bufobj != NULL);
duk__set_bufobj_buffer(ctx, h_bufobj, h_val);
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
return 1;
fail_length:
DUK_DCERROR_RANGE_INVALID_LENGTH(thr);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/* Format of magic, bits:
* 0...1: elem size shift (0-3)
* 2...5: elem type (DUK_HBUFOBJ_ELEM_xxx)
*
* XXX: add prototype bidx explicitly to magic instead of using a mapping?
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_typedarray_constructor(duk_context *ctx) {
duk_hthread *thr;
duk_tval *tv;
duk_hobject *h_obj;
duk_hbufobj *h_bufobj = NULL;
duk_hbufobj *h_bufarr = NULL;
duk_hbufobj *h_bufarg = NULL;
duk_hbuffer *h_val;
duk_small_uint_t magic;
duk_small_uint_t shift;
duk_small_uint_t elem_type;
duk_small_uint_t elem_size;
duk_small_uint_t class_num;
duk_small_uint_t proto_bidx;
duk_uint_t align_mask;
duk_uint_t elem_length;
duk_int_t elem_length_signed;
duk_uint_t byte_length;
duk_small_uint_t copy_mode;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
/* XXX: The same copy helpers could be shared with at least some
* buffer functions.
*/
duk_require_constructor_call(ctx);
/* We could fit built-in index into magic but that'd make the magic
* number dependent on built-in numbering (genbuiltins.py doesn't
* handle that yet). So map both class and prototype from the
* element type.
*/
magic = duk_get_current_magic(ctx);
shift = magic & 0x03; /* bits 0...1: shift */
elem_type = (magic >> 2) & 0x0f; /* bits 2...5: type */
elem_size = 1 << shift;
align_mask = elem_size - 1;
DUK_ASSERT(elem_type < sizeof(duk__buffer_proto_from_elemtype) / sizeof(duk_uint8_t));
proto_bidx = duk__buffer_proto_from_elemtype[elem_type];
DUK_ASSERT(proto_bidx < DUK_NUM_BUILTINS);
DUK_ASSERT(elem_type < sizeof(duk__buffer_class_from_elemtype) / sizeof(duk_uint8_t));
class_num = duk__buffer_class_from_elemtype[elem_type];
DUK_DD(DUK_DDPRINT("typedarray constructor, magic=%d, shift=%d, elem_type=%d, "
"elem_size=%d, proto_bidx=%d, class_num=%d",
(int) magic, (int) shift, (int) elem_type, (int) elem_size,
(int) proto_bidx, (int) class_num));
/* Argument variants. When the argument is an ArrayBuffer a view to
* the same buffer is created; otherwise a new ArrayBuffer is always
* created.
*/
/* XXX: initial iteration to treat a plain buffer like an ArrayBuffer:
* coerce to an ArrayBuffer object and use that as .buffer. The underlying
* buffer will be the same but result .buffer !== inputPlainBuffer.
*/
duk_hbufobj_promote_plain(ctx, 0);
tv = duk_get_tval(ctx, 0);
DUK_ASSERT(tv != NULL); /* arg count */
if (DUK_TVAL_IS_OBJECT(tv)) {
h_obj = DUK_TVAL_GET_OBJECT(tv);
DUK_ASSERT(h_obj != NULL);
if (DUK_HOBJECT_GET_CLASS_NUMBER(h_obj) == DUK_HOBJECT_CLASS_ARRAYBUFFER) {
/* ArrayBuffer: unlike any other argument variant, create
* a view into the existing buffer.
*/
duk_int_t byte_offset_signed;
duk_uint_t byte_offset;
h_bufarg = (duk_hbufobj *) h_obj;
byte_offset_signed = duk_to_int(ctx, 1);
if (byte_offset_signed < 0) {
goto fail_arguments;
}
byte_offset = (duk_uint_t) byte_offset_signed;
if (byte_offset > h_bufarg->length ||
(byte_offset & align_mask) != 0) {
/* Must be >= 0 and multiple of element size. */
goto fail_arguments;
}
if (duk_is_undefined(ctx, 2)) {
DUK_ASSERT(h_bufarg->length >= byte_offset);
byte_length = h_bufarg->length - byte_offset;
if ((byte_length & align_mask) != 0) {
/* Must be element size multiple from
* start offset to end of buffer.
*/
goto fail_arguments;
}
elem_length = (byte_length >> shift);
} else {
elem_length_signed = duk_to_int(ctx, 2);
if (elem_length_signed < 0) {
goto fail_arguments;
}
elem_length = (duk_uint_t) elem_length_signed;
byte_length = elem_length << shift;
if ((byte_length >> shift) != elem_length) {
/* Byte length would overflow. */
/* XXX: easier check with less code? */
goto fail_arguments;
}
DUK_ASSERT(h_bufarg->length >= byte_offset);
if (byte_length > h_bufarg->length - byte_offset) {
/* Not enough data. */
goto fail_arguments;
}
}
DUK_UNREF(elem_length);
DUK_ASSERT_DISABLE(byte_offset >= 0);
DUK_ASSERT(byte_offset <= h_bufarg->length);
DUK_ASSERT_DISABLE(byte_length >= 0);
DUK_ASSERT(byte_offset + byte_length <= h_bufarg->length);
DUK_ASSERT((elem_length << shift) == byte_length);
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(class_num),
proto_bidx);
h_val = h_bufarg->buf;
if (h_val == NULL) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
h_bufobj->buf = h_val;
DUK_HBUFFER_INCREF(thr, h_val);
h_bufobj->offset = h_bufarg->offset + byte_offset;
h_bufobj->length = byte_length;
h_bufobj->shift = (duk_uint8_t) shift;
h_bufobj->elem_type = (duk_uint8_t) elem_type;
h_bufobj->is_view = 1;
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
/* Set .buffer to the argument ArrayBuffer. */
duk_dup_0(ctx);
duk_xdef_prop_stridx_short(ctx, -2, DUK_STRIDX_LC_BUFFER, DUK_PROPDESC_FLAGS_NONE);
duk_compact_m1(ctx);
return 1;
} else if (DUK_HOBJECT_IS_BUFOBJ(h_obj)) {
/* TypedArray (or other non-ArrayBuffer duk_hbufobj).
* Conceptually same behavior as for an Array-like argument,
* with a few fast paths.
*/
h_bufarg = (duk_hbufobj *) h_obj;
DUK_ASSERT_HBUFOBJ_VALID(h_bufarg);
elem_length_signed = (duk_int_t) (h_bufarg->length >> h_bufarg->shift);
if (h_bufarg->buf == NULL) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
/* Select copy mode. Must take into account element
* compatibility and validity of the underlying source
* buffer.
*/
DUK_DDD(DUK_DDDPRINT("selecting copy mode for bufobj arg, "
"src byte_length=%ld, src shift=%d, "
"src/dst elem_length=%ld; "
"dst shift=%d -> dst byte_length=%ld",
(long) h_bufarg->length, (int) h_bufarg->shift,
(long) elem_length_signed, (int) shift,
(long) (elem_length_signed << shift)));
copy_mode = 2; /* default is explicit index read/write copy */
#if !defined(DUK_USE_PREFER_SIZE)
/* With a size optimized build copy_mode 2 is enough.
* Modes 0 and 1 are faster but conceptually the same.
*/
DUK_ASSERT(elem_type < sizeof(duk__buffer_elemtype_copy_compatible) / sizeof(duk_uint16_t));
if (DUK_HBUFOBJ_VALID_SLICE(h_bufarg)) {
if ((duk__buffer_elemtype_copy_compatible[elem_type] & (1 << h_bufarg->elem_type)) != 0) {
DUK_DDD(DUK_DDDPRINT("source/target are copy compatible, memcpy"));
DUK_ASSERT(shift == h_bufarg->shift); /* byte sizes will match */
copy_mode = 0;
} else {
DUK_DDD(DUK_DDDPRINT("source/target not copy compatible but valid, fast copy"));
copy_mode = 1;
}
}
#endif /* !DUK_USE_PREFER_SIZE */
} else {
/* Array or Array-like */
elem_length_signed = (duk_int_t) duk_get_length(ctx, 0);
copy_mode = 2;
}
} else {
/* Non-object argument is simply int coerced, matches
* V8 behavior (except for "null", which we coerce to
* 0 but V8 TypeErrors).
*/
elem_length_signed = duk_to_int(ctx, 0);
copy_mode = 3;
}
if (elem_length_signed < 0) {
goto fail_arguments;
}
elem_length = (duk_uint_t) elem_length_signed;
byte_length = (duk_uint_t) (elem_length << shift);
if ((byte_length >> shift) != elem_length) {
/* Byte length would overflow. */
/* XXX: easier check with less code? */
goto fail_arguments;
}
DUK_DDD(DUK_DDDPRINT("elem_length=%ld, byte_length=%ld",
(long) elem_length, (long) byte_length));
/* ArrayBuffer argument is handled specially above; the rest of the
* argument variants are handled by shared code below.
*/
/* Push a new ArrayBuffer (becomes view .buffer) */
h_bufarr = duk__push_arraybuffer_with_length(ctx, byte_length);
DUK_ASSERT(h_bufarr != NULL);
h_val = h_bufarr->buf;
DUK_ASSERT(h_val != NULL);
/* Push the resulting view object and attach the ArrayBuffer. */
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(class_num),
proto_bidx);
h_bufobj->buf = h_val;
DUK_HBUFFER_INCREF(thr, h_val);
DUK_ASSERT(h_bufobj->offset == 0);
h_bufobj->length = byte_length;
h_bufobj->shift = (duk_uint8_t) shift;
h_bufobj->elem_type = (duk_uint8_t) elem_type;
h_bufobj->is_view = 1;
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
/* Set .buffer */
duk_dup_m2(ctx);
duk_xdef_prop_stridx_short(ctx, -2, DUK_STRIDX_LC_BUFFER, DUK_PROPDESC_FLAGS_NONE);
duk_compact_m1(ctx);
/* Copy values, the copy method depends on the arguments.
*
* Copy mode decision may depend on the validity of the underlying
* buffer of the source argument; there must be no harmful side effects
* from there to here for copy_mode to still be valid.
*/
DUK_DDD(DUK_DDDPRINT("copy mode: %d", (int) copy_mode));
switch (copy_mode) {
/* Copy modes 0 and 1 can be omitted in size optimized build,
* copy mode 2 handles them (but more slowly).
*/
#if !defined(DUK_USE_PREFER_SIZE)
case 0: {
/* Use byte copy. */
duk_uint8_t *p_src;
duk_uint8_t *p_dst;
DUK_ASSERT(h_bufobj != NULL);
DUK_ASSERT(h_bufobj->buf != NULL);
DUK_ASSERT(DUK_HBUFOBJ_VALID_SLICE(h_bufobj));
DUK_ASSERT(h_bufarg != NULL);
DUK_ASSERT(h_bufarg->buf != NULL);
DUK_ASSERT(DUK_HBUFOBJ_VALID_SLICE(h_bufarg));
p_dst = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufobj);
p_src = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufarg);
DUK_DDD(DUK_DDDPRINT("using memcpy: p_src=%p, p_dst=%p, byte_length=%ld",
(void *) p_src, (void *) p_dst, (long) byte_length));
DUK_MEMCPY((void *) p_dst, (const void *) p_src, (size_t) byte_length);
break;
}
case 1: {
/* Copy values through direct validated reads and writes. */
duk_small_uint_t src_elem_size;
duk_small_uint_t dst_elem_size;
duk_uint8_t *p_src;
duk_uint8_t *p_src_end;
duk_uint8_t *p_dst;
DUK_ASSERT(h_bufobj != NULL);
DUK_ASSERT(h_bufobj->buf != NULL);
DUK_ASSERT(DUK_HBUFOBJ_VALID_SLICE(h_bufobj));
DUK_ASSERT(h_bufarg != NULL);
DUK_ASSERT(h_bufarg->buf != NULL);
DUK_ASSERT(DUK_HBUFOBJ_VALID_SLICE(h_bufarg));
src_elem_size = 1 << h_bufarg->shift;
dst_elem_size = elem_size;
p_src = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufarg);
p_dst = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufobj);
p_src_end = p_src + h_bufarg->length;
DUK_DDD(DUK_DDDPRINT("using fast copy: p_src=%p, p_src_end=%p, p_dst=%p, "
"src_elem_size=%d, dst_elem_size=%d",
(void *) p_src, (void *) p_src_end, (void *) p_dst,
(int) src_elem_size, (int) dst_elem_size));
while (p_src != p_src_end) {
DUK_DDD(DUK_DDDPRINT("fast path per element copy loop: "
"p_src=%p, p_src_end=%p, p_dst=%p",
(void *) p_src, (void *) p_src_end, (void *) p_dst));
/* A validated read() is always a number, so it's write coercion
* is always side effect free an won't invalidate pointers etc.
*/
duk_hbufobj_push_validated_read(ctx, h_bufarg, p_src, src_elem_size);
duk_hbufobj_validated_write(ctx, h_bufobj, p_dst, dst_elem_size);
duk_pop(ctx);
p_src += src_elem_size;
p_dst += dst_elem_size;
}
break;
}
#endif /* !DUK_USE_PREFER_SIZE */
case 2: {
/* Copy values by index reads and writes. Let virtual
* property handling take care of coercion.
*/
duk_uint_t i;
DUK_DDD(DUK_DDDPRINT("using slow copy"));
for (i = 0; i < elem_length; i++) {
duk_get_prop_index(ctx, 0, (duk_uarridx_t) i);
duk_put_prop_index(ctx, -2, (duk_uarridx_t) i);
}
break;
}
default:
case 3: {
/* No copy, leave zero bytes in the buffer. There's no
* ambiguity with Float32/Float64 because zero bytes also
* represent 0.0.
*/
#if !defined(DUK_USE_ZERO_BUFFER_DATA)
/* Khronos/ES6 requires zeroing even when DUK_USE_ZERO_BUFFER_DATA
* is not set.
*/
DUK_ASSERT(!DUK_HBUFFER_HAS_DYNAMIC((duk_hbuffer *) h_val));
DUK_MEMZERO((void *) DUK_HBUFFER_FIXED_GET_DATA_PTR(thr->heap, h_val), (duk_size_t) byte_length);
#endif
DUK_DDD(DUK_DDDPRINT("using no copy"));
break;
}
}
return 1;
fail_arguments:
DUK_DCERROR_RANGE_INVALID_ARGS(thr);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_dataview_constructor(duk_context *ctx) {
duk_hbufobj *h_bufarg;
duk_hbufobj *h_bufobj;
duk_hbuffer *h_val;
duk_uint_t offset;
duk_uint_t length;
duk_require_constructor_call(ctx);
h_bufarg = duk__require_bufobj_value(ctx, 0);
DUK_ASSERT(h_bufarg != NULL);
duk__resolve_offset_opt_length(ctx, h_bufarg, 1, 2, &offset, &length, 1 /*throw_flag*/);
DUK_ASSERT(offset <= h_bufarg->length);
DUK_ASSERT(offset + length <= h_bufarg->length);
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_DATAVIEW),
DUK_BIDX_DATAVIEW_PROTOTYPE);
h_val = h_bufarg->buf;
if (h_val == NULL) {
DUK_DCERROR_TYPE_INVALID_ARGS((duk_hthread *) ctx);
}
h_bufobj->buf = h_val;
DUK_HBUFFER_INCREF(thr, h_val);
h_bufobj->offset = h_bufarg->offset + offset;
h_bufobj->length = length;
DUK_ASSERT(h_bufobj->shift == 0);
DUK_ASSERT(h_bufobj->elem_type == DUK_HBUFOBJ_ELEM_UINT8);
h_bufobj->is_view = 1;
/* The DataView .buffer property is ordinarily set to the argument
* which is an ArrayBuffer. We accept any duk_hbufobj as
* an argument and .buffer will be set to the argument regardless
* of what it is. This may be a bit confusing if the argument
* is e.g. a DataView or another TypedArray view.
*
* XXX: Copy .buffer property from a DataView/TypedArray argument?
* Create a fresh ArrayBuffer for Node.js Buffer argument?
* See: test-bug-dataview-buffer-prop.js.
*/
duk_dup_0(ctx);
duk_xdef_prop_stridx_short(ctx, -2, DUK_STRIDX_LC_BUFFER, DUK_PROPDESC_FLAGS_NONE);
duk_compact_m1(ctx);
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* ArrayBuffer.isView()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_arraybuffer_isview(duk_context *ctx) {
duk_hobject *h_obj;
duk_bool_t ret = 0;
h_obj = duk_get_hobject(ctx, 0);
if (h_obj != NULL && DUK_HOBJECT_IS_BUFOBJ(h_obj)) {
ret = ((duk_hbufobj *) h_obj)->is_view;
}
duk_push_boolean(ctx, ret);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* ArrayBuffer.allocPlain()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_arraybuffer_allocplain(duk_context *ctx) {
duk__hbufobj_fixed_from_argvalue(ctx);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* ArrayBuffer.plainOf()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_arraybuffer_plainof(duk_context *ctx) {
duk_hbufobj *h_bufobj;
#if !defined(DUK_USE_PREFER_SIZE)
/* Avoid churn if argument is already a plain buffer. */
if (duk_is_buffer(ctx, 0)) {
return 1;
}
#endif
/* Promotes plain buffers to ArrayBuffers, so for a plain buffer
* argument we'll create a pointless temporary (but still work
* correctly).
*/
h_bufobj = duk__require_bufobj_value(ctx, 0);
if (h_bufobj->buf == NULL) {
duk_push_undefined(ctx);
} else {
duk_push_hbuffer(ctx, h_bufobj->buf);
}
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer: toString([encoding], [start], [end])
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_tostring(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_this;
duk_int_t start_offset, end_offset;
duk_uint8_t *buf_slice;
duk_size_t slice_length;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
h_this = duk__get_bufobj_this(ctx);
if (h_this == NULL) {
/* XXX: happens e.g. when evaluating: String(Buffer.prototype). */
duk_push_string(ctx, "[object Object]");
return 1;
}
DUK_ASSERT_HBUFOBJ_VALID(h_this);
/* Ignore encoding for now. */
duk__clamp_startend_nonegidx_noshift(ctx,
(duk_int_t) h_this->length,
1 /*idx_start*/,
2 /*idx_end*/,
&start_offset,
&end_offset);
slice_length = (duk_size_t) (end_offset - start_offset);
buf_slice = (duk_uint8_t *) duk_push_fixed_buffer_nozero(ctx, slice_length); /* all bytes initialized below */
DUK_ASSERT(buf_slice != NULL);
/* Neutered or uncovered, TypeError. */
if (h_this->buf == NULL ||
!DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_this, start_offset + slice_length)) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
/* XXX: ideally we wouldn't make a copy but a view into the buffer for the
* decoding process. Or the decoding helper could be changed to accept
* the slice info (a buffer pointer is NOT a good approach because guaranteeing
* its stability is difficult).
*/
DUK_ASSERT(DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_this, start_offset + slice_length));
DUK_MEMCPY((void *) buf_slice,
(const void *) (DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this) + start_offset),
(size_t) slice_length);
/* Use the equivalent of: new TextEncoder().encode(this) to convert the
* string. Result will be valid UTF-8; non-CESU-8 inputs are currently
* interpreted loosely. Value stack convention is a bit odd for now.
*/
duk_replace(ctx, 0);
duk_set_top(ctx, 1);
return duk_textdecoder_decode_utf8_nodejs(ctx);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.prototype: toJSON()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_tojson(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_this;
duk_harray *h_arr;
duk_uint8_t *buf;
duk_uint_t i, n;
duk_tval *tv;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
h_this = duk__require_bufobj_this(ctx);
DUK_ASSERT(h_this != NULL);
if (h_this->buf == NULL || !DUK_HBUFOBJ_VALID_SLICE(h_this)) {
/* Serialize uncovered backing buffer as a null; doesn't
* really matter as long we're memory safe.
*/
duk_push_null(ctx);
return 1;
}
duk_push_object(ctx);
duk_push_hstring_stridx(ctx, DUK_STRIDX_UC_BUFFER);
duk_put_prop_stridx_short(ctx, -2, DUK_STRIDX_TYPE);
DUK_ASSERT_DISABLE((duk_size_t) h_this->length <= (duk_size_t) DUK_UINT32_MAX);
h_arr = duk_push_harray_with_size(ctx, (duk_uint32_t) h_this->length); /* XXX: needs revision with >4G buffers */
DUK_ASSERT(h_arr != NULL);
DUK_ASSERT(h_arr->length == h_this->length);
tv = DUK_HOBJECT_A_GET_BASE(thr->heap, (duk_hobject *) h_arr);
DUK_ASSERT(h_this->buf != NULL);
buf = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this);
for (i = 0, n = h_this->length; i < n; i++) {
DUK_TVAL_SET_U32(tv + i, (duk_uint32_t) buf[i]); /* no need for decref or incref */
}
duk_put_prop_stridx_short(ctx, -2, DUK_STRIDX_DATA);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.prototype.equals()
* Node.js Buffer.prototype.compare()
* Node.js Buffer.compare()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_buffer_compare_shared(duk_context *ctx) {
duk_hthread *thr;
duk_small_uint_t magic;
duk_hbufobj *h_bufarg1;
duk_hbufobj *h_bufarg2;
duk_small_int_t comp_res;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
/* XXX: keep support for plain buffers and non-Node.js buffers? */
magic = duk_get_current_magic(ctx);
if (magic & 0x02) {
/* Static call style. */
h_bufarg1 = duk__require_bufobj_value(ctx, 0);
h_bufarg2 = duk__require_bufobj_value(ctx, 1);
} else {
h_bufarg1 = duk__require_bufobj_this(ctx);
h_bufarg2 = duk__require_bufobj_value(ctx, 0);
}
DUK_ASSERT(h_bufarg1 != NULL);
DUK_ASSERT(h_bufarg2 != NULL);
/* We want to compare the slice/view areas of the arguments.
* If either slice/view is invalid (underlying buffer is shorter)
* ensure equals() is false, but otherwise the only thing that
* matters is to be memory safe.
*/
if (DUK_HBUFOBJ_VALID_SLICE(h_bufarg1) &&
DUK_HBUFOBJ_VALID_SLICE(h_bufarg2)) {
comp_res = duk_js_data_compare((const duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_bufarg1->buf) + h_bufarg1->offset,
(const duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_bufarg2->buf) + h_bufarg2->offset,
(duk_size_t) h_bufarg1->length,
(duk_size_t) h_bufarg2->length);
} else {
comp_res = -1; /* either nonzero value is ok */
}
if (magic & 0x01) {
/* compare: similar to string comparison but for buffer data. */
duk_push_int(ctx, comp_res);
} else {
/* equals */
duk_push_boolean(ctx, (comp_res == 0));
}
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.prototype.fill()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_fill(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_this;
const duk_uint8_t *fill_str_ptr;
duk_size_t fill_str_len;
duk_uint8_t fill_value;
duk_int_t fill_offset;
duk_int_t fill_end;
duk_size_t fill_length;
duk_uint8_t *p;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
h_this = duk__require_bufobj_this(ctx);
DUK_ASSERT(h_this != NULL);
if (h_this->buf == NULL) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
/* [ value offset end ] */
if (duk_is_string_notsymbol(ctx, 0)) {
fill_str_ptr = (const duk_uint8_t *) duk_get_lstring(ctx, 0, &fill_str_len);
DUK_ASSERT(fill_str_ptr != NULL);
} else {
/* Symbols get ToNumber() coerced and cause TypeError. */
fill_value = (duk_uint8_t) duk_to_uint32(ctx, 0);
fill_str_ptr = (const duk_uint8_t *) &fill_value;
fill_str_len = 1;
}
/* Fill offset handling is more lenient than in Node.js. */
duk__clamp_startend_nonegidx_noshift(ctx,
(duk_int_t) h_this->length,
1 /*idx_start*/,
2 /*idx_end*/,
&fill_offset,
&fill_end);
DUK_DDD(DUK_DDDPRINT("fill: fill_value=%02x, fill_offset=%ld, fill_end=%ld, view length=%ld",
(unsigned int) fill_value, (long) fill_offset, (long) fill_end, (long) h_this->length));
DUK_ASSERT(fill_end - fill_offset >= 0);
DUK_ASSERT(h_this->buf != NULL);
p = (DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this) + fill_offset);
fill_length = (duk_size_t) (fill_end - fill_offset);
if (fill_str_len == 1) {
/* Handle single character fills as memset() even when
* the fill data comes from a one-char argument.
*/
DUK_MEMSET((void *) p, (int) fill_str_ptr[0], (size_t) fill_length);
} else if (fill_str_len > 1) {
duk_size_t i, n, t;
for (i = 0, n = (fill_end - fill_offset), t = 0; i < n; i++) {
p[i] = fill_str_ptr[t++];
if (t >= fill_str_len) {
t = 0;
}
}
} else {
DUK_DDD(DUK_DDDPRINT("zero size fill pattern, ignore silently"));
}
/* Return the Buffer to allow chaining: b.fill(0x11).fill(0x22, 3, 5).toString() */
duk_push_this(ctx);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.prototype.write(string, [offset], [length], [encoding])
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_write(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_this;
duk_uint_t offset;
duk_uint_t length;
const duk_uint8_t *str_data;
duk_size_t str_len;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
/* XXX: very inefficient support for plain buffers */
h_this = duk__require_bufobj_this(ctx);
DUK_ASSERT(h_this != NULL);
/* Argument must be a string, e.g. a buffer is not allowed. */
str_data = (const duk_uint8_t *) duk_require_lstring_notsymbol(ctx, 0, &str_len);
duk__resolve_offset_opt_length(ctx, h_this, 1, 2, &offset, &length, 0 /*throw_flag*/);
DUK_ASSERT(offset <= h_this->length);
DUK_ASSERT(offset + length <= h_this->length);
/* XXX: encoding is ignored now. */
if (length > str_len) {
length = (duk_uint_t) str_len;
}
if (DUK_HBUFOBJ_VALID_SLICE(h_this)) {
/* Cannot overlap. */
DUK_MEMCPY((void *) (DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this) + offset),
(const void *) str_data,
(size_t) length);
} else {
DUK_DDD(DUK_DDDPRINT("write() target buffer is not covered, silent ignore"));
}
duk_push_uint(ctx, length);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.prototype.copy()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_copy(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_this;
duk_hbufobj *h_bufarg;
duk_int_t source_length;
duk_int_t target_length;
duk_int_t target_start, source_start, source_end;
duk_uint_t target_ustart, source_ustart, source_uend;
duk_uint_t copy_size = 0;
/* [ targetBuffer targetStart sourceStart sourceEnd ] */
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
h_this = duk__require_bufobj_this(ctx);
h_bufarg = duk__require_bufobj_value(ctx, 0);
DUK_ASSERT(h_this != NULL);
DUK_ASSERT(h_bufarg != NULL);
source_length = (duk_int_t) h_this->length;
target_length = (duk_int_t) h_bufarg->length;
target_start = duk_to_int(ctx, 1);
source_start = duk_to_int(ctx, 2);
if (duk_is_undefined(ctx, 3)) {
source_end = source_length;
} else {
source_end = duk_to_int(ctx, 3);
}
DUK_DDD(DUK_DDDPRINT("checking copy args: target_start=%ld, target_length=%ld, "
"source_start=%ld, source_end=%ld, source_length=%ld",
(long) target_start, (long) h_bufarg->length,
(long) source_start, (long) source_end, (long) source_length));
/* This behavior mostly mimics Node.js now. */
if (source_start < 0 || source_end < 0 || target_start < 0) {
/* Negative offsets cause a RangeError. */
goto fail_bounds;
}
source_ustart = (duk_uint_t) source_start;
source_uend = (duk_uint_t) source_end;
target_ustart = (duk_uint_t) target_start;
if (source_ustart >= source_uend || /* crossed offsets or zero size */
source_ustart >= (duk_uint_t) source_length || /* source out-of-bounds (but positive) */
target_ustart >= (duk_uint_t) target_length) { /* target out-of-bounds (but positive) */
goto silent_ignore;
}
if (source_uend >= (duk_uint_t) source_length) {
/* Source end clamped silently to available length. */
source_uend = source_length;
}
copy_size = source_uend - source_ustart;
if (target_ustart + copy_size > (duk_uint_t) target_length) {
/* Clamp to target's end if too long.
*
* NOTE: there's no overflow possibility in the comparison;
* both target_ustart and copy_size are >= 0 and based on
* values in duk_int_t range. Adding them as duk_uint_t
* values is then guaranteed not to overflow.
*/
DUK_ASSERT(target_ustart + copy_size >= target_ustart); /* no overflow */
DUK_ASSERT(target_ustart + copy_size >= copy_size); /* no overflow */
copy_size = (duk_uint_t) target_length - target_ustart;
}
DUK_DDD(DUK_DDDPRINT("making copy: target_ustart=%lu source_ustart=%lu copy_size=%lu",
(unsigned long) target_ustart, (unsigned long) source_ustart,
(unsigned long) copy_size));
DUK_ASSERT(copy_size >= 1);
DUK_ASSERT(source_ustart <= (duk_uint_t) source_length);
DUK_ASSERT(source_ustart + copy_size <= (duk_uint_t) source_length);
DUK_ASSERT(target_ustart <= (duk_uint_t) target_length);
DUK_ASSERT(target_ustart + copy_size <= (duk_uint_t) target_length);
/* Ensure copy is covered by underlying buffers. */
DUK_ASSERT(h_bufarg->buf != NULL); /* length check */
DUK_ASSERT(h_this->buf != NULL); /* length check */
if (DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_bufarg, target_ustart + copy_size) &&
DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_this, source_ustart + copy_size)) {
/* Must use memmove() because copy area may overlap (source and target
* buffer may be the same, or from different slices.
*/
DUK_MEMMOVE((void *) (DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufarg) + target_ustart),
(const void *) (DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this) + source_ustart),
(size_t) copy_size);
} else {
DUK_DDD(DUK_DDDPRINT("buffer copy not covered by underlying buffer(s), ignoring"));
}
silent_ignore:
/* Return value is like write(), number of bytes written.
* The return value matters because of code like:
* "off += buf.copy(...)".
*/
duk_push_uint(ctx, copy_size);
return 1;
fail_bounds:
DUK_DCERROR_RANGE_INVALID_ARGS(thr);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* TypedArray.prototype.set()
*
* TypedArray set() is pretty interesting to implement because:
*
* - The source argument may be a plain array or a typedarray. If the
* source is a TypedArray, values are decoded and re-encoded into the
* target (not as a plain byte copy). This may happen even when the
* element byte size is the same, e.g. integer values may be re-encoded
* into floats.
*
* - Source and target may refer to the same underlying buffer, so that
* the set() operation may overlap. The specification requires that this
* must work as if a copy was made before the operation. Note that this
* is NOT a simple memmove() situation because the source and target
* byte sizes may be different -- e.g. a 4-byte source (Int8Array) may
* expand to a 16-byte target (Uint32Array) so that the target overlaps
* the source both from beginning and the end (unlike in typical memmove).
*
* - Even if 'buf' pointers of the source and target differ, there's no
* guarantee that their memory areas don't overlap. This may be the
* case with external buffers.
*
* Even so, it is nice to optimize for the common case:
*
* - Source and target separate buffers or non-overlapping.
*
* - Source and target have a compatible type so that a plain byte copy
* is possible. Note that while e.g. uint8 and int8 are compatible
* (coercion one way or another doesn't change the byte representation),
* e.g. int8 and uint8clamped are NOT compatible when writing int8
* values into uint8clamped typedarray (-1 would clamp to 0 for instance).
*
* See test-bi-typedarray-proto-set.js.
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_typedarray_set(duk_context *ctx) {
duk_hthread *thr;
duk_hbufobj *h_this;
duk_hobject *h_obj;
duk_uarridx_t i, n;
duk_int_t offset_signed;
duk_uint_t offset_elems;
duk_uint_t offset_bytes;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
h_this = duk__require_bufobj_this(ctx);
DUK_ASSERT(h_this != NULL);
DUK_ASSERT_HBUFOBJ_VALID(h_this);
if (h_this->buf == NULL) {
DUK_DDD(DUK_DDDPRINT("source neutered, skip copy"));
return 0;
}
duk_hbufobj_promote_plain(ctx, 0);
h_obj = duk_known_hobject(ctx, 0);
/* XXX: V8 throws a TypeError for negative values. Would it
* be more useful to interpret negative offsets here from the
* end of the buffer too?
*/
offset_signed = duk_to_int(ctx, 1);
if (offset_signed < 0) {
/* For some reason this is a TypeError (at least in V8). */
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
offset_elems = (duk_uint_t) offset_signed;
offset_bytes = offset_elems << h_this->shift;
if ((offset_bytes >> h_this->shift) != offset_elems) {
/* Byte length would overflow. */
/* XXX: easier check with less code? */
goto fail_args;
}
if (offset_bytes > h_this->length) {
/* Equality may be OK but >length not. Checking
* this explicitly avoids some overflow cases
* below.
*/
goto fail_args;
}
DUK_ASSERT(offset_bytes <= h_this->length);
/* Fast path: source is a TypedArray (or any bufobj). */
if (DUK_HOBJECT_IS_BUFOBJ(h_obj)) {
duk_hbufobj *h_bufarg;
#if !defined(DUK_USE_PREFER_SIZE)
duk_uint16_t comp_mask;
#endif
duk_small_int_t no_overlap = 0;
duk_uint_t src_length;
duk_uint_t dst_length;
duk_uint_t dst_length_elems;
duk_uint8_t *p_src_base;
duk_uint8_t *p_src_end;
duk_uint8_t *p_src;
duk_uint8_t *p_dst_base;
duk_uint8_t *p_dst;
duk_small_uint_t src_elem_size;
duk_small_uint_t dst_elem_size;
h_bufarg = (duk_hbufobj *) h_obj;
DUK_ASSERT_HBUFOBJ_VALID(h_bufarg);
if (h_bufarg->buf == NULL) {
DUK_DDD(DUK_DDDPRINT("target neutered, skip copy"));
return 0;
}
/* Nominal size check. */
src_length = h_bufarg->length; /* bytes in source */
dst_length_elems = (src_length >> h_bufarg->shift); /* elems in source and dest */
dst_length = dst_length_elems << h_this->shift; /* bytes in dest */
if ((dst_length >> h_this->shift) != dst_length_elems) {
/* Byte length would overflow. */
/* XXX: easier check with less code? */
goto fail_args;
}
DUK_DDD(DUK_DDDPRINT("nominal size check: src_length=%ld, dst_length=%ld",
(long) src_length, (long) dst_length));
DUK_ASSERT(offset_bytes <= h_this->length);
if (dst_length > h_this->length - offset_bytes) {
/* Overflow not an issue because subtraction is used on the right
* side and guaranteed to be >= 0.
*/
DUK_DDD(DUK_DDDPRINT("copy exceeds target buffer nominal length"));
goto fail_args;
}
if (!DUK_HBUFOBJ_VALID_BYTEOFFSET_EXCL(h_this, offset_bytes + dst_length)) {
DUK_DDD(DUK_DDDPRINT("copy not covered by underlying target buffer, ignore"));
return 0;
}
p_src_base = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufarg);
p_dst_base = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this) + offset_bytes;
/* Check actual underlying buffers for validity and that they
* cover the copy. No side effects are allowed after the check
* so that the validity status doesn't change.
*/
if (!DUK_HBUFOBJ_VALID_SLICE(h_this) ||
!DUK_HBUFOBJ_VALID_SLICE(h_bufarg)) {
/* The condition could be more narrow and check for the
* copy area only, but there's no need for fine grained
* behavior when the underlying buffer is misconfigured.
*/
DUK_DDD(DUK_DDDPRINT("source and/or target not covered by underlying buffer, skip copy"));
return 0;
}
/* We want to do a straight memory copy if possible: this is
* an important operation because .set() is the TypedArray
* way to copy chunks of memory. However, because set()
* conceptually works in terms of elements, not all views are
* compatible with direct byte copying.
*
* If we do manage a direct copy, the "overlap issue" handled
* below can just be solved using memmove() because the source
* and destination element sizes are necessarily equal.
*/
#if !defined(DUK_USE_PREFER_SIZE)
DUK_ASSERT(h_this->elem_type < sizeof(duk__buffer_elemtype_copy_compatible) / sizeof(duk_uint16_t));
comp_mask = duk__buffer_elemtype_copy_compatible[h_this->elem_type];
if (comp_mask & (1 << h_bufarg->elem_type)) {
DUK_ASSERT(src_length == dst_length);
DUK_DDD(DUK_DDDPRINT("fast path: able to use memmove() because views are compatible"));
DUK_MEMMOVE((void *) p_dst_base, (const void *) p_src_base, (size_t) dst_length);
return 0;
}
DUK_DDD(DUK_DDDPRINT("fast path: views are not compatible with a byte copy, copy by item"));
#endif /* !DUK_USE_PREFER_SIZE */
/* We want to avoid making a copy to process set() but that's
* not always possible: the source and the target may overlap
* and because element sizes are different, the overlap cannot
* always be handled with a memmove() or choosing the copy
* direction in a certain way. For example, if source type is
* uint8 and target type is uint32, the target area may exceed
* the source area from both ends!
*
* Note that because external buffers may point to the same
* memory areas, we must ultimately make this check using
* pointers.
*
* NOTE: careful with side effects: any side effect may cause
* a buffer resize (or external buffer pointer/length update)!
*/
DUK_DDD(DUK_DDDPRINT("overlap check: p_src_base=%p, src_length=%ld, "
"p_dst_base=%p, dst_length=%ld",
(void *) p_src_base, (long) src_length,
(void *) p_dst_base, (long) dst_length));
if (p_src_base >= p_dst_base + dst_length || /* source starts after dest ends */
p_src_base + src_length <= p_dst_base) { /* source ends before dest starts */
no_overlap = 1;
}
if (!no_overlap) {
/* There's overlap: the desired end result is that
* conceptually a copy is made to avoid "trampling"
* of source data by destination writes. We make
* an actual temporary copy to handle this case.
*/
duk_uint8_t *p_src_copy;
DUK_DDD(DUK_DDDPRINT("there is overlap, make a copy of the source"));
p_src_copy = (duk_uint8_t *) duk_push_fixed_buffer_nozero(ctx, src_length);
DUK_ASSERT(p_src_copy != NULL);
DUK_MEMCPY((void *) p_src_copy, (const void *) p_src_base, (size_t) src_length);
p_src_base = p_src_copy; /* use p_src_base from now on */
}
/* Value stack intentionally mixed size here. */
DUK_DDD(DUK_DDDPRINT("after overlap check: p_src_base=%p, src_length=%ld, "
"p_dst_base=%p, dst_length=%ld, valstack top=%ld",
(void *) p_src_base, (long) src_length,
(void *) p_dst_base, (long) dst_length,
(long) duk_get_top(ctx)));
/* Ready to make the copy. We must proceed element by element
* and must avoid any side effects that might cause the buffer
* validity check above to become invalid.
*
* Although we work through the value stack here, only plain
* numbers are handled which should be side effect safe.
*/
src_elem_size = 1 << h_bufarg->shift;
dst_elem_size = 1 << h_this->shift;
p_src = p_src_base;
p_dst = p_dst_base;
p_src_end = p_src_base + src_length;
while (p_src != p_src_end) {
DUK_DDD(DUK_DDDPRINT("fast path per element copy loop: "
"p_src=%p, p_src_end=%p, p_dst=%p",
(void *) p_src, (void *) p_src_end, (void *) p_dst));
/* A validated read() is always a number, so it's write coercion
* is always side effect free an won't invalidate pointers etc.
*/
duk_hbufobj_push_validated_read(ctx, h_bufarg, p_src, src_elem_size);
duk_hbufobj_validated_write(ctx, h_this, p_dst, dst_elem_size);
duk_pop(ctx);
p_src += src_elem_size;
p_dst += dst_elem_size;
}
return 0;
} else {
/* Slow path: quite slow, but we save space by using the property code
* to write coerce target values. We don't need to worry about overlap
* here because the source is not a TypedArray.
*
* We could use the bufobj write coercion helper but since the
* property read may have arbitrary side effects, full validity checks
* would be needed for every element anyway.
*/
n = (duk_uarridx_t) duk_get_length(ctx, 0);
DUK_ASSERT(offset_bytes <= h_this->length);
if ((n << h_this->shift) > h_this->length - offset_bytes) {
/* Overflow not an issue because subtraction is used on the right
* side and guaranteed to be >= 0.
*/
DUK_DDD(DUK_DDDPRINT("copy exceeds target buffer nominal length"));
goto fail_args;
}
/* There's no need to check for buffer validity status for the
* target here: the property access code will do that for each
* element. Moreover, if we did check the validity here, side
* effects from reading the source argument might invalidate
* the results anyway.
*/
DUK_ASSERT_TOP(ctx, 2);
duk_push_this(ctx);
for (i = 0; i < n; i++) {
duk_get_prop_index(ctx, 0, i);
duk_put_prop_index(ctx, 2, offset_elems + i);
}
}
return 0;
fail_args:
DUK_DCERROR_RANGE_INVALID_ARGS(thr);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.prototype.slice([start], [end])
* ArrayBuffer.prototype.slice(begin, [end])
* TypedArray.prototype.subarray(begin, [end])
*
* The API calls are almost identical; negative indices are counted from end
* of buffer, and final indices are clamped (allowing crossed indices). Main
* differences:
*
* - Copy/view behavior; Node.js .slice() and TypedArray .subarray() create
* views, ArrayBuffer .slice() creates a copy
*
* - Resulting object has a different class and prototype depending on the
* call (or 'this' argument)
*
* - TypedArray .subarray() arguments are element indices, not byte offsets
*
* - Plain buffer argument creates a plain buffer slice
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_LOCAL void duk__arraybuffer_plain_slice(duk_context *ctx, duk_hbuffer *h_val) {
duk_hthread *thr;
duk_int_t start_offset, end_offset;
duk_uint_t slice_length;
duk_uint8_t *p_copy;
duk_size_t copy_length;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
duk__clamp_startend_negidx_shifted(ctx,
(duk_int_t) DUK_HBUFFER_GET_SIZE(h_val),
0 /*buffer_shift*/,
0 /*idx_start*/,
1 /*idx_end*/,
&start_offset,
&end_offset);
DUK_ASSERT(end_offset <= (duk_int_t) DUK_HBUFFER_GET_SIZE(h_val));
DUK_ASSERT(start_offset >= 0);
DUK_ASSERT(end_offset >= start_offset);
slice_length = (duk_uint_t) (end_offset - start_offset);
p_copy = (duk_uint8_t *) duk_push_fixed_buffer_nozero(ctx, (duk_size_t) slice_length);
DUK_ASSERT(p_copy != NULL);
copy_length = slice_length;
DUK_MEMCPY((void *) p_copy,
(const void *) ((duk_uint8_t *) DUK_HBUFFER_GET_DATA_PTR(thr->heap, h_val) + start_offset),
copy_length);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
/* Shared helper for slice/subarray operation.
* Magic: 0x01=isView, 0x02=copy, 0x04=Node.js Buffer special handling.
*/
DUK_INTERNAL duk_ret_t duk_bi_buffer_slice_shared(duk_context *ctx) {
duk_hthread *thr;
duk_small_int_t magic;
duk_small_uint_t res_class_num;
duk_small_int_t res_proto_bidx;
duk_hbufobj *h_this;
duk_hbufobj *h_bufobj;
duk_hbuffer *h_val;
duk_int_t start_offset, end_offset;
duk_uint_t slice_length;
duk_tval *tv;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
/* [ start end ] */
magic = duk_get_current_magic(ctx);
tv = duk_get_borrowed_this_tval(ctx);
DUK_ASSERT(tv != NULL);
if (DUK_TVAL_IS_BUFFER(tv)) {
/* For plain buffers return a plain buffer slice. */
h_val = DUK_TVAL_GET_BUFFER(tv);
DUK_ASSERT(h_val != NULL);
if (magic & 0x02) {
/* Make copy: ArrayBuffer.prototype.slice() uses this. */
duk__arraybuffer_plain_slice(ctx, h_val);
return 1;
} else {
/* View into existing buffer: cannot be done if the
* result is a plain buffer because there's no slice
* info. So return an ArrayBuffer instance; coerce
* the 'this' binding into an object and behave as if
* the original call was for an Object-coerced plain
* buffer (handled automatically by duk__require_bufobj_this()).
*/
DUK_DDD(DUK_DDDPRINT("slice() doesn't handle view into plain buffer, coerce 'this' to ArrayBuffer object"));
/* fall through */
}
}
tv = NULL; /* No longer valid nor needed. */
h_this = duk__require_bufobj_this(ctx);
/* Slice offsets are element (not byte) offsets, which only matters
* for TypedArray views, Node.js Buffer and ArrayBuffer have shift
* zero so byte and element offsets are the same. Negative indices
* are counted from end of slice, crossed indices are allowed (and
* result in zero length result), and final values are clamped
* against the current slice. There's intentionally no check
* against the underlying buffer here.
*/
duk__clamp_startend_negidx_shifted(ctx,
(duk_int_t) h_this->length,
(duk_uint8_t) h_this->shift,
0 /*idx_start*/,
1 /*idx_end*/,
&start_offset,
&end_offset);
DUK_ASSERT(end_offset >= start_offset);
slice_length = (duk_uint_t) (end_offset - start_offset);
/* The resulting buffer object gets the same class and prototype as
* the buffer in 'this', e.g. if the input is a Uint8Array the
* result is a Uint8Array; if the input is a Float32Array, the
* result is a Float32Array. The result internal prototype should
* be the default prototype for the class (e.g. initial value of
* Uint8Array.prototype), not copied from the argument (Duktape 1.x
* did that).
*
* Node.js Buffers have special handling: they're Uint8Arrays as far
* as the internal class is concerned, so the new Buffer should also
* be an Uint8Array but inherit from Buffer.prototype.
*/
res_class_num = DUK_HOBJECT_GET_CLASS_NUMBER((duk_hobject *) h_this);
DUK_ASSERT(res_class_num >= DUK_HOBJECT_CLASS_BUFOBJ_MIN); /* type check guarantees */
DUK_ASSERT(res_class_num <= DUK_HOBJECT_CLASS_BUFOBJ_MAX);
res_proto_bidx = duk__buffer_proto_from_classnum[res_class_num - DUK_HOBJECT_CLASS_BUFOBJ_MIN];
if (magic & 0x04) {
res_proto_bidx = DUK_BIDX_NODEJS_BUFFER_PROTOTYPE;
}
h_bufobj = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(res_class_num),
res_proto_bidx);
DUK_ASSERT(h_bufobj != NULL);
h_bufobj->length = slice_length;
h_bufobj->shift = h_this->shift; /* inherit */
h_bufobj->elem_type = h_this->elem_type; /* inherit */
h_bufobj->is_view = magic & 0x01;
DUK_ASSERT(h_bufobj->is_view == 0 || h_bufobj->is_view == 1);
h_val = h_this->buf;
if (h_val == NULL) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
if (magic & 0x02) {
/* non-zero: make copy */
duk_uint8_t *p_copy;
duk_size_t copy_length;
p_copy = (duk_uint8_t *) duk_push_fixed_buffer(ctx, (duk_size_t) slice_length); /* must be zeroed, not all bytes always copied */
DUK_ASSERT(p_copy != NULL);
/* Copy slice, respecting underlying buffer limits; remainder
* is left as zero.
*/
copy_length = DUK_HBUFOBJ_CLAMP_BYTELENGTH(h_this, slice_length);
DUK_MEMCPY((void *) p_copy,
(const void *) (DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this) + start_offset),
copy_length);
h_val = duk_known_hbuffer(ctx, -1);
h_bufobj->buf = h_val;
DUK_HBUFFER_INCREF(thr, h_val);
DUK_ASSERT(h_bufobj->offset == 0);
duk_pop(ctx); /* reachable so pop OK */
} else {
h_bufobj->buf = h_val;
DUK_HBUFFER_INCREF(thr, h_val);
h_bufobj->offset = (duk_uint_t) (h_this->offset + start_offset);
/* Copy the .buffer property, needed for TypedArray.prototype.subarray().
*
* XXX: limit copy only for TypedArray classes specifically?
*/
duk_push_this(ctx);
if (duk_get_prop_stridx_short(ctx, -1, DUK_STRIDX_LC_BUFFER)) {
duk_xdef_prop_stridx_short(ctx, -3, DUK_STRIDX_LC_BUFFER, DUK_PROPDESC_FLAGS_NONE);
duk_pop(ctx);
} else {
duk_pop_2(ctx);
}
}
/* unbalanced stack on purpose */
DUK_ASSERT_HBUFOBJ_VALID(h_bufobj);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.isEncoding()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_is_encoding(duk_context *ctx) {
const char *encoding;
/* only accept lowercase 'utf8' now. */
encoding = duk_to_string(ctx, 0);
DUK_ASSERT(duk_is_string(ctx, 0)); /* guaranteed by duk_to_string() */
duk_push_boolean(ctx, DUK_STRCMP(encoding, "utf8") == 0);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.isBuffer()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_is_buffer(duk_context *ctx) {
duk_hthread *thr;
duk_hobject *h;
duk_hobject *h_proto;
duk_bool_t ret = 0;
thr = (duk_hthread *) ctx;
DUK_ASSERT(duk_get_top(ctx) >= 1); /* nargs */
h = duk_get_hobject(ctx, 0);
if (h != NULL) {
h_proto = thr->builtins[DUK_BIDX_NODEJS_BUFFER_PROTOTYPE];
DUK_ASSERT(h_proto != NULL);
h = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h);
if (h != NULL) {
ret = duk_hobject_prototype_chain_contains(thr, h, h_proto, 0 /*ignore_loop*/);
}
}
duk_push_boolean(ctx, ret);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.byteLength()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_byte_length(duk_context *ctx) {
const char *str;
duk_size_t len;
/* At the moment Buffer(<str>) will just use the string bytes as
* is (ignoring encoding), so we return the string length here
* unconditionally.
*/
/* XXX: to be revised; Old Node.js behavior just coerces any buffer
* values to string:
* $ node
* > Buffer.byteLength(new Uint32Array(10))
* 20
* > Buffer.byteLength(new Uint32Array(100))
* 20
* (The 20 comes from '[object Uint32Array]'.length
*/
str = duk_to_lstring(ctx, 0, &len);
DUK_UNREF(str);
duk_push_size_t(ctx, len);
return 1;
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Node.js Buffer.concat()
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
DUK_INTERNAL duk_ret_t duk_bi_nodejs_buffer_concat(duk_context *ctx) {
duk_hthread *thr;
duk_hobject *h_arg;
duk_int_t total_length = 0;
duk_hbufobj *h_bufobj;
duk_hbufobj *h_bufres;
duk_hbuffer *h_val;
duk_uint_t i, n;
duk_uint8_t *p;
duk_size_t space_left;
duk_size_t copy_size;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
/* Node.js accepts only actual Arrays. */
h_arg = duk_require_hobject(ctx, 0);
if (DUK_HOBJECT_GET_CLASS_NUMBER(h_arg) != DUK_HOBJECT_CLASS_ARRAY) {
DUK_DCERROR_TYPE_INVALID_ARGS(thr);
}
/* Compute result length and validate argument buffers. */
n = (duk_uint_t) duk_get_length(ctx, 0);
for (i = 0; i < n; i++) {
/* Neutered checks not necessary here: neutered buffers have
* zero 'length' so we'll effectively skip them.
*/
DUK_ASSERT_TOP(ctx, 2); /* [ array totalLength ] */
duk_get_prop_index(ctx, 0, (duk_uarridx_t) i); /* -> [ array totalLength buf ] */
h_bufobj = duk__require_bufobj_value(ctx, 2);
DUK_ASSERT(h_bufobj != NULL);
total_length += h_bufobj->length;
duk_pop(ctx);
}
/* In Node.js v0.12.1 a 1-element array is special and won't create a
* copy, this was fixed later so an explicit check no longer needed.
*/
/* User totalLength overrides a computed length, but we'll check
* every copy in the copy loop. Note that duk_to_uint() can
* technically have arbitrary side effects so we need to recheck
* the buffers in the copy loop.
*/
if (!duk_is_undefined(ctx, 1) && n > 0) {
/* For n == 0, Node.js ignores totalLength argument and
* returns a zero length buffer.
*/
total_length = duk_to_int(ctx, 1);
}
if (total_length < 0) {
DUK_DCERROR_RANGE_INVALID_ARGS(thr);
}
h_bufres = duk_push_bufobj_raw(ctx,
DUK_HOBJECT_FLAG_EXTENSIBLE |
DUK_HOBJECT_FLAG_BUFOBJ |
DUK_HOBJECT_CLASS_AS_FLAGS(DUK_HOBJECT_CLASS_UINT8ARRAY),
DUK_BIDX_NODEJS_BUFFER_PROTOTYPE);
DUK_ASSERT(h_bufres != NULL);
p = (duk_uint8_t *) duk_push_fixed_buffer(ctx, total_length); /* must be zeroed, all bytes not necessarily written over */
DUK_ASSERT(p != NULL);
space_left = total_length;
for (i = 0; i < n; i++) {
DUK_ASSERT_TOP(ctx, 4); /* [ array totalLength bufres buf ] */
duk_get_prop_index(ctx, 0, (duk_uarridx_t) i);
h_bufobj = duk__require_bufobj_value(ctx, 4);
DUK_ASSERT(h_bufobj != NULL);
copy_size = h_bufobj->length;
if (copy_size > space_left) {
copy_size = space_left;
}
if (h_bufobj->buf != NULL &&
DUK_HBUFOBJ_VALID_SLICE(h_bufobj)) {
DUK_MEMCPY((void *) p,
(const void *) DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_bufobj),
copy_size);
} else {
/* Just skip, leaving zeroes in the result. */
;
}
p += copy_size;
space_left -= copy_size;
duk_pop(ctx);
}
h_val = duk_known_hbuffer(ctx, -1);
duk__set_bufobj_buffer(ctx, h_bufres, h_val);
DUK_ASSERT_HBUFOBJ_VALID(h_bufres);
duk_pop(ctx); /* pop plain buffer, now reachable through h_bufres */
return 1; /* return h_bufres */
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
/*
* Shared readfield and writefield methods
*
* The readfield/writefield methods need support for endianness and field
* types. All offsets are byte based so no offset shifting is needed.
*/
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
/* Format of magic, bits:
* 0...1: field type; 0=uint8, 1=uint16, 2=uint32, 3=float, 4=double, 5=unused, 6=unused, 7=unused
* 3: endianness: 0=little, 1=big
* 4: signed: 1=yes, 0=no
* 5: typedarray: 1=yes, 0=no
*/
#define DUK__FLD_8BIT 0
#define DUK__FLD_16BIT 1
#define DUK__FLD_32BIT 2
#define DUK__FLD_FLOAT 3
#define DUK__FLD_DOUBLE 4
#define DUK__FLD_VARINT 5
#define DUK__FLD_BIGENDIAN (1 << 3)
#define DUK__FLD_SIGNED (1 << 4)
#define DUK__FLD_TYPEDARRAY (1 << 5)
/* XXX: split into separate functions for each field type? */
DUK_INTERNAL duk_ret_t duk_bi_buffer_readfield(duk_context *ctx) {
duk_hthread *thr;
duk_small_int_t magic = (duk_small_int_t) duk_get_current_magic(ctx);
duk_small_int_t magic_ftype;
duk_small_int_t magic_bigendian;
duk_small_int_t magic_signed;
duk_small_int_t magic_typedarray;
duk_small_int_t endswap;
duk_hbufobj *h_this;
duk_bool_t no_assert;
duk_int_t offset_signed;
duk_uint_t offset;
duk_uint_t buffer_length;
duk_uint_t check_length;
duk_uint8_t *buf;
duk_double_union du;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
magic_ftype = magic & 0x0007;
magic_bigendian = magic & 0x0008;
magic_signed = magic & 0x0010;
magic_typedarray = magic & 0x0020;
h_this = duk__require_bufobj_this(ctx); /* XXX: very inefficient for plain buffers */
DUK_ASSERT(h_this != NULL);
buffer_length = h_this->length;
/* [ offset noAssert ], when ftype != DUK__FLD_VARINT */
/* [ offset fieldByteLength noAssert ], when ftype == DUK__FLD_VARINT */
/* [ offset littleEndian ], when DUK__FLD_TYPEDARRAY (regardless of ftype) */
/* Handle TypedArray vs. Node.js Buffer arg differences */
if (magic_typedarray) {
no_assert = 0;
#if defined(DUK_USE_INTEGER_LE)
endswap = !duk_to_boolean(ctx, 1); /* 1=little endian */
#else
endswap = duk_to_boolean(ctx, 1); /* 1=little endian */
#endif
} else {
no_assert = duk_to_boolean(ctx, (magic_ftype == DUK__FLD_VARINT) ? 2 : 1);
#if defined(DUK_USE_INTEGER_LE)
endswap = magic_bigendian;
#else
endswap = !magic_bigendian;
#endif
}
/* Offset is coerced first to signed integer range and then to unsigned.
* This ensures we can add a small byte length (1-8) to the offset in
* bound checks and not wrap.
*/
offset_signed = duk_to_int(ctx, 0);
offset = (duk_uint_t) offset_signed;
if (offset_signed < 0) {
goto fail_bounds;
}
DUK_DDD(DUK_DDDPRINT("readfield, buffer_length=%ld, offset=%ld, no_assert=%d, "
"magic=%04x, magic_fieldtype=%d, magic_bigendian=%d, magic_signed=%d, "
"endswap=%d",
(long) buffer_length, (long) offset, (int) no_assert,
(unsigned int) magic, (int) magic_ftype, (int) (magic_bigendian >> 3),
(int) (magic_signed >> 4), (int) endswap));
/* Update 'buffer_length' to be the effective, safe limit which
* takes into account the underlying buffer. This value will be
* potentially invalidated by any side effect.
*/
check_length = DUK_HBUFOBJ_CLAMP_BYTELENGTH(h_this, buffer_length);
DUK_DDD(DUK_DDDPRINT("buffer_length=%ld, check_length=%ld",
(long) buffer_length, (long) check_length));
if (h_this->buf) {
buf = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this);
} else {
/* Neutered. We could go into the switch-case safely with
* buf == NULL because check_length == 0. To avoid scanbuild
* warnings, fail directly instead.
*/
DUK_ASSERT(check_length == 0);
goto fail_neutered;
}
DUK_ASSERT(buf != NULL);
switch (magic_ftype) {
case DUK__FLD_8BIT: {
duk_uint8_t tmp;
if (offset + 1U > check_length) {
goto fail_bounds;
}
tmp = buf[offset];
if (magic_signed) {
duk_push_int(ctx, (duk_int_t) ((duk_int8_t) tmp));
} else {
duk_push_uint(ctx, (duk_uint_t) tmp);
}
break;
}
case DUK__FLD_16BIT: {
duk_uint16_t tmp;
if (offset + 2U > check_length) {
goto fail_bounds;
}
DUK_MEMCPY((void *) du.uc, (const void *) (buf + offset), 2);
tmp = du.us[0];
if (endswap) {
tmp = DUK_BSWAP16(tmp);
}
if (magic_signed) {
duk_push_int(ctx, (duk_int_t) ((duk_int16_t) tmp));
} else {
duk_push_uint(ctx, (duk_uint_t) tmp);
}
break;
}
case DUK__FLD_32BIT: {
duk_uint32_t tmp;
if (offset + 4U > check_length) {
goto fail_bounds;
}
DUK_MEMCPY((void *) du.uc, (const void *) (buf + offset), 4);
tmp = du.ui[0];
if (endswap) {
tmp = DUK_BSWAP32(tmp);
}
if (magic_signed) {
duk_push_int(ctx, (duk_int_t) ((duk_int32_t) tmp));
} else {
duk_push_uint(ctx, (duk_uint_t) tmp);
}
break;
}
case DUK__FLD_FLOAT: {
duk_uint32_t tmp;
if (offset + 4U > check_length) {
goto fail_bounds;
}
DUK_MEMCPY((void *) du.uc, (const void *) (buf + offset), 4);
if (endswap) {
tmp = du.ui[0];
tmp = DUK_BSWAP32(tmp);
du.ui[0] = tmp;
}
duk_push_number(ctx, (duk_double_t) du.f[0]);
break;
}
case DUK__FLD_DOUBLE: {
if (offset + 8U > check_length) {
goto fail_bounds;
}
DUK_MEMCPY((void *) du.uc, (const void *) (buf + offset), 8);
if (endswap) {
DUK_DBLUNION_BSWAP64(&du);
}
duk_push_number(ctx, (duk_double_t) du.d);
break;
}
case DUK__FLD_VARINT: {
/* Node.js Buffer variable width integer field. We don't really
* care about speed here, so aim for shortest algorithm.
*/
duk_int_t field_bytelen;
duk_int_t i, i_step, i_end;
#if defined(DUK_USE_64BIT_OPS)
duk_int64_t tmp;
duk_small_uint_t shift_tmp;
#else
duk_double_t tmp;
duk_small_int_t highbyte;
#endif
const duk_uint8_t *p;
field_bytelen = duk_get_int(ctx, 1); /* avoid side effects! */
if (field_bytelen < 1 || field_bytelen > 6) {
goto fail_field_length;
}
if (offset + (duk_uint_t) field_bytelen > check_length) {
goto fail_bounds;
}
p = (const duk_uint8_t *) (buf + offset);
/* Slow gathering of value using either 64-bit arithmetic
* or IEEE doubles if 64-bit types not available. Handling
* of negative numbers is a bit non-obvious in both cases.
*/
if (magic_bigendian) {
/* Gather in big endian */
i = 0;
i_step = 1;
i_end = field_bytelen; /* one i_step over */
} else {
/* Gather in little endian */
i = field_bytelen - 1;
i_step = -1;
i_end = -1; /* one i_step over */
}
#if defined(DUK_USE_64BIT_OPS)
tmp = 0;
do {
DUK_ASSERT(i >= 0 && i < field_bytelen);
tmp = (tmp << 8) + (duk_int64_t) p[i];
i += i_step;
} while (i != i_end);
if (magic_signed) {
/* Shift to sign extend. */
shift_tmp = 64 - (field_bytelen * 8);
tmp = (tmp << shift_tmp) >> shift_tmp;
}
duk_push_i64(ctx, tmp);
#else
highbyte = p[i];
if (magic_signed && (highbyte & 0x80) != 0) {
/* 0xff => 255 - 256 = -1; 0x80 => 128 - 256 = -128 */
tmp = (duk_double_t) (highbyte - 256);
} else {
tmp = (duk_double_t) highbyte;
}
for (;;) {
i += i_step;
if (i == i_end) {
break;
}
DUK_ASSERT(i >= 0 && i < field_bytelen);
tmp = (tmp * 256.0) + (duk_double_t) p[i];
}
duk_push_number(ctx, tmp);
#endif
break;
}
default: { /* should never happen but default here */
goto fail_bounds;
}
}
return 1;
fail_neutered:
fail_field_length:
fail_bounds:
if (no_assert) {
/* Node.js return value for noAssert out-of-bounds reads is
* usually (but not always) NaN. Return NaN consistently.
*/
duk_push_nan(ctx);
return 1;
}
DUK_DCERROR_RANGE_INVALID_ARGS(thr);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */
#if defined(DUK_USE_BUFFEROBJECT_SUPPORT)
/* XXX: split into separate functions for each field type? */
DUK_INTERNAL duk_ret_t duk_bi_buffer_writefield(duk_context *ctx) {
duk_hthread *thr;
duk_small_int_t magic = (duk_small_int_t) duk_get_current_magic(ctx);
duk_small_int_t magic_ftype;
duk_small_int_t magic_bigendian;
duk_small_int_t magic_signed;
duk_small_int_t magic_typedarray;
duk_small_int_t endswap;
duk_hbufobj *h_this;
duk_bool_t no_assert;
duk_int_t offset_signed;
duk_uint_t offset;
duk_uint_t buffer_length;
duk_uint_t check_length;
duk_uint8_t *buf;
duk_double_union du;
duk_int_t nbytes = 0;
thr = (duk_hthread *) ctx;
DUK_UNREF(thr);
magic_ftype = magic & 0x0007;
magic_bigendian = magic & 0x0008;
magic_signed = magic & 0x0010;
magic_typedarray = magic & 0x0020;
DUK_UNREF(magic_signed);
h_this = duk__require_bufobj_this(ctx); /* XXX: very inefficient for plain buffers */
DUK_ASSERT(h_this != NULL);
buffer_length = h_this->length;
/* [ value offset noAssert ], when ftype != DUK__FLD_VARINT */
/* [ value offset fieldByteLength noAssert ], when ftype == DUK__FLD_VARINT */
/* [ offset value littleEndian ], when DUK__FLD_TYPEDARRAY (regardless of ftype) */
/* Handle TypedArray vs. Node.js Buffer arg differences */
if (magic_typedarray) {
no_assert = 0;
#if defined(DUK_USE_INTEGER_LE)
endswap = !duk_to_boolean(ctx, 2); /* 1=little endian */
#else
endswap = duk_to_boolean(ctx, 2); /* 1=little endian */
#endif
duk_swap(ctx, 0, 1); /* offset/value order different from Node.js */
} else {
no_assert = duk_to_boolean(ctx, (magic_ftype == DUK__FLD_VARINT) ? 3 : 2);
#if defined(DUK_USE_INTEGER_LE)
endswap = magic_bigendian;
#else
endswap = !magic_bigendian;
#endif
}
/* Offset is coerced first to signed integer range and then to unsigned.
* This ensures we can add a small byte length (1-8) to the offset in
* bound checks and not wrap.
*/
offset_signed = duk_to_int(ctx, 1);
offset = (duk_uint_t) offset_signed;
/* We need 'nbytes' even for a failed offset; return value must be
* (offset + nbytes) even when write fails due to invalid offset.
*/
if (magic_ftype != DUK__FLD_VARINT) {
DUK_ASSERT(magic_ftype >= 0 && magic_ftype < (duk_small_int_t) (sizeof(duk__buffer_nbytes_from_fldtype) / sizeof(duk_uint8_t)));
nbytes = duk__buffer_nbytes_from_fldtype[magic_ftype];
} else {
nbytes = duk_get_int(ctx, 2);
if (nbytes < 1 || nbytes > 6) {
goto fail_field_length;
}
}
DUK_ASSERT(nbytes >= 1 && nbytes <= 8);
/* Now we can check offset validity. */
if (offset_signed < 0) {
goto fail_bounds;
}
DUK_DDD(DUK_DDDPRINT("writefield, value=%!T, buffer_length=%ld, offset=%ld, no_assert=%d, "
"magic=%04x, magic_fieldtype=%d, magic_bigendian=%d, magic_signed=%d, "
"endswap=%d",
duk_get_tval(ctx, 0), (long) buffer_length, (long) offset, (int) no_assert,
(unsigned int) magic, (int) magic_ftype, (int) (magic_bigendian >> 3),
(int) (magic_signed >> 4), (int) endswap));
/* Coerce value to a number before computing check_length, so that
* the field type specific coercion below can't have side effects
* that would invalidate check_length.
*/
duk_to_number(ctx, 0);
/* Update 'buffer_length' to be the effective, safe limit which
* takes into account the underlying buffer. This value will be
* potentially invalidated by any side effect.
*/
check_length = DUK_HBUFOBJ_CLAMP_BYTELENGTH(h_this, buffer_length);
DUK_DDD(DUK_DDDPRINT("buffer_length=%ld, check_length=%ld",
(long) buffer_length, (long) check_length));
if (h_this->buf) {
buf = DUK_HBUFOBJ_GET_SLICE_BASE(thr->heap, h_this);
} else {
/* Neutered. We could go into the switch-case safely with
* buf == NULL because check_length == 0. To avoid scanbuild
* warnings, fail directly instead.
*/
DUK_ASSERT(check_length == 0);
goto fail_neutered;
}
DUK_ASSERT(buf != NULL);
switch (magic_ftype) {
case DUK__FLD_8BIT: {
if (offset + 1U > check_length) {
goto fail_bounds;
}
/* sign doesn't matter when writing */
buf[offset] = (duk_uint8_t) duk_to_uint32(ctx, 0);
break;
}
case DUK__FLD_16BIT: {
duk_uint16_t tmp;
if (offset + 2U > check_length) {
goto fail_bounds;
}
tmp = (duk_uint16_t) duk_to_uint32(ctx, 0);
if (endswap) {
tmp = DUK_BSWAP16(tmp);
}
du.us[0] = tmp;
/* sign doesn't matter when writing */
DUK_MEMCPY((void *) (buf + offset), (const void *) du.uc, 2);
break;
}
case DUK__FLD_32BIT: {
duk_uint32_t tmp;
if (offset + 4U > check_length) {
goto fail_bounds;
}
tmp = (duk_uint32_t) duk_to_uint32(ctx, 0);
if (endswap) {
tmp = DUK_BSWAP32(tmp);
}
du.ui[0] = tmp;
/* sign doesn't matter when writing */
DUK_MEMCPY((void *) (buf + offset), (const void *) du.uc, 4);
break;
}
case DUK__FLD_FLOAT: {
duk_uint32_t tmp;
if (offset + 4U > check_length) {
goto fail_bounds;
}
du.f[0] = (duk_float_t) duk_to_number(ctx, 0);
if (endswap) {
tmp = du.ui[0];
tmp = DUK_BSWAP32(tmp);
du.ui[0] = tmp;
}
/* sign doesn't matter when writing */
DUK_MEMCPY((void *) (buf + offset), (const void *) du.uc, 4);
break;
}
case DUK__FLD_DOUBLE: {
if (offset + 8U > check_length) {
goto fail_bounds;
}
du.d = (duk_double_t) duk_to_number(ctx, 0);
if (endswap) {
DUK_DBLUNION_BSWAP64(&du);
}
/* sign doesn't matter when writing */
DUK_MEMCPY((void *) (buf + offset), (const void *) du.uc, 8);
break;
}
case DUK__FLD_VARINT: {
/* Node.js Buffer variable width integer field. We don't really
* care about speed here, so aim for shortest algorithm.
*/
duk_int_t field_bytelen;
duk_int_t i, i_step, i_end;
#if defined(DUK_USE_64BIT_OPS)
duk_int64_t tmp;
#else
duk_double_t tmp;
#endif
duk_uint8_t *p;
field_bytelen = (duk_int_t) nbytes;
if (offset + (duk_uint_t) field_bytelen > check_length) {
goto fail_bounds;
}
/* Slow writing of value using either 64-bit arithmetic
* or IEEE doubles if 64-bit types not available. There's
* no special sign handling when writing varints.
*/
if (magic_bigendian) {
/* Write in big endian */
i = field_bytelen; /* one i_step added at top of loop */
i_step = -1;
i_end = 0;
} else {
/* Write in little endian */
i = -1; /* one i_step added at top of loop */
i_step = 1;
i_end = field_bytelen - 1;
}
/* XXX: The duk_to_number() cast followed by integer coercion
* is platform specific so NaN, +/- Infinity, and out-of-bounds
* values result in platform specific output now.
* See: test-bi-nodejs-buffer-proto-varint-special.js
*/
#if defined(DUK_USE_64BIT_OPS)
tmp = (duk_int64_t) duk_to_number(ctx, 0);
p = (duk_uint8_t *) (buf + offset);
do {
i += i_step;
DUK_ASSERT(i >= 0 && i < field_bytelen);
p[i] = (duk_uint8_t) (tmp & 0xff);
tmp = tmp >> 8; /* unnecessary shift for last byte */
} while (i != i_end);
#else
tmp = duk_to_number(ctx, 0);
p = (duk_uint8_t *) (buf + offset);
do {
i += i_step;
tmp = DUK_FLOOR(tmp);
DUK_ASSERT(i >= 0 && i < field_bytelen);
p[i] = (duk_uint8_t) (DUK_FMOD(tmp, 256.0));
tmp = tmp / 256.0; /* unnecessary div for last byte */
} while (i != i_end);
#endif
break;
}
default: { /* should never happen but default here */
goto fail_bounds;
}
}
/* Node.js Buffer: return offset + #bytes written (i.e. next
* write offset).
*/
if (magic_typedarray) {
/* For TypedArrays 'undefined' return value is specified
* by ES6 (matches V8).
*/
return 0;
}
duk_push_uint(ctx, offset + nbytes);
return 1;
fail_neutered:
fail_field_length:
fail_bounds:
if (no_assert) {
/* Node.js return value for failed writes is offset + #bytes
* that would have been written.
*/
/* XXX: for negative input offsets, 'offset' will be a large
* positive value so the result here is confusing.
*/
if (magic_typedarray) {
return 0;
}
duk_push_uint(ctx, offset + nbytes);
return 1;
}
DUK_DCERROR_RANGE_INVALID_ARGS(thr);
}
#endif /* DUK_USE_BUFFEROBJECT_SUPPORT */