duktape/tests/api/test-get-buffer-data.c

/*===
*** test_basic (duk_safe_call)
top: 18
index 0: length 0
index 1: length 0
index 2: length 0
index 3: length 0
index 4: length 0
index 5: length 0
index 6: length 0
index 7: length 0
index 8: length 0
index 9: length 1024, ptr-is-NULL 0
index 10: length 0
index 11: length 2048, ptr-is-NULL 0
index 12: length 16, ptr-is-NULL 0
index 13: length 64, ptr-is-NULL 0
index 14: length 16, ptr-is-NULL 0
index 15: length 12, ptr-is-NULL 0
index 16: length 8, ptr-is-NULL 0
index 17: length 3, ptr-is-NULL 0
final top: 18
==> rc=0, result='undefined'
===*/

static duk_ret_t test_basic(duk_context *ctx, void *udata) {
	duk_idx_t i, n;

	(void) udata;

	duk_push_undefined(ctx);
	duk_push_null(ctx);
	duk_push_true(ctx);
	duk_push_false(ctx);
	duk_push_string(ctx, "");
	duk_push_string(ctx, "foo");
	duk_push_int(ctx, 123);
	duk_push_object(ctx);
	duk_push_fixed_buffer(ctx, 0);
	duk_push_fixed_buffer(ctx, 1024);
	duk_push_dynamic_buffer(ctx, 0);
	duk_push_dynamic_buffer(ctx, 2048);
	duk_eval_string(ctx, "(function () { return new ArrayBuffer(16); })()");
	duk_eval_string(ctx, "(function () { return new Uint32Array(16); })()");
	duk_eval_string(ctx, "(function () { return new DataView(new ArrayBuffer(16)); })()");
	duk_eval_string(ctx, "(function () { return new Uint32Array(16).subarray(3, 6); })()");
	duk_eval_string(ctx, "(function () { return new Buffer('ABCDEFGH'); })()");
	duk_eval_string(ctx, "(function () { return new Buffer('ABCDEFGH').slice(3, 6); })()");

	n = duk_get_top(ctx);
	printf("top: %ld\n", (long) n);
	for (i = 0; i < n; i++) {
		void *buf;
		duk_size_t len;

		len = (duk_size_t) 0xdeadbeefUL;
		buf = duk_get_buffer_data(ctx, i, &len);
		if (len == 0) {
			/* avoid printing 'buf' if len is zero, as it is not predictable */
			printf("index %ld: length 0\n", (long) i);
		} else {
			printf("index %ld: length %lu, ptr-is-NULL %d\n",
			       (long) i, (unsigned long) len, (buf == NULL ? 1 : 0));
		}
	}

	printf("final top: %ld\n", (long) duk_get_top(ctx));
	return 0;
}

/*===
*** test_null_ptr (duk_safe_call)
p is not NULL
final top: 1
==> rc=0, result='undefined'
===*/

static duk_ret_t test_null_ptr(duk_context *ctx, void *udata) {
	void *p;

	(void) udata;

	duk_eval_string(ctx,
		"(function () {\n"
		"    var b = new ArrayBuffer(16);\n"
		"    var v = new Uint32Array(b);\n"
		"    v.set([ 0x11111111, 0x22222222, 0x33333333, 0x44444444 ]);\n"
		"    return v.subarray(1, 3);\n"
		"})()");

	p = duk_get_buffer_data(ctx, -1, NULL);
	if (p) {
		printf("p is not NULL\n");
	} else {
		printf("p is NULL\n");
	}

	printf("final top: %ld\n", (long) duk_get_top(ctx));
	return 0;
}

/*===
*** test_slice (duk_safe_call)
p is not NULL, sz=8
p[0] = 0x22
p[1] = 0x22
p[2] = 0x22
p[3] = 0x22
p[4] = 0x33
p[5] = 0x33
p[6] = 0x33
p[7] = 0x33
final top: 1
==> rc=0, result='undefined'
===*/

/* Test that slice views work, i.e. returned buffer pointer
 * is correctly offsetted.  Avoid endianness by using initializers
 * which have the same memory representation in either case.
 */
static duk_ret_t test_slice(duk_context *ctx, void *udata) {
	unsigned char *p;
	duk_size_t sz;
	duk_size_t i;

	(void) udata;

	duk_eval_string(ctx,
		"(function () {\n"
		"    var b = new ArrayBuffer(16);\n"
		"    var v = new Uint32Array(b);\n"
		"    v.set([ 0x11111111, 0x22222222, 0x33333333, 0x44444444 ]);\n"
		"    return v.subarray(1, 3);\n"
		"})()");

	sz = (duk_size_t) 0xdeadbeefUL;
	p = duk_get_buffer_data(ctx, -1, &sz);
	if (p) {
		printf("p is not NULL, sz=%ld\n", (long) sz);
		for (i = 0; i < sz; i++) {
			printf("p[%ld] = 0x%02x\n", (long) i, (unsigned int) p[i]);
		}
	} else {
		printf("p is NULL\n");
	}

	printf("final top: %ld\n", (long) duk_get_top(ctx));
	return 0;
}

/*===
*** test_uncovered_buffer (duk_safe_call)
p is not NULL, sz=16
p is not NULL, sz=16
p is NULL
final top: 2
==> rc=0, result='undefined'
===*/

/* Underlying buffer doesn't cover logical slice. */
static duk_ret_t test_uncovered_buffer(duk_context *ctx, void *udata) {
	unsigned char *p;
	duk_size_t sz;

	(void) udata;

	duk_push_dynamic_buffer(ctx, 64);  /* 16x4 elements */

	duk_eval_string(ctx,
		"(function (plain_buffer) {\n"
		"    var b = Object(plain_buffer);\n"
		"    return new Uint32Array(b).subarray(1,5);\n"
		"})");
	duk_dup(ctx, 0);
	duk_call(ctx, 1);  /* -> [ plain_buffer Uint32Array ] */

	/* Initially OK. */
	sz = (duk_size_t) 0xdeadbeefUL;
	p = duk_get_buffer_data(ctx, -1, &sz);
	if (p) {
		printf("p is not NULL, sz=%ld\n", (long) sz);
	} else {
		printf("p is NULL\n");
	}

	/* Resize; slice still covered. */
	duk_resize_buffer(ctx, 0, 20);  /* 5x4 = 20, subarray is [1*4, 5*4[ */
	sz = (duk_size_t) 0xdeadbeefUL;
	p = duk_get_buffer_data(ctx, -1, &sz);
	if (p) {
		printf("p is not NULL, sz=%ld\n", (long) sz);
	} else {
		printf("p is NULL\n");
	}

	/* Resize; no longer covered. */
	duk_resize_buffer(ctx, 0, 19);
	sz = (duk_size_t) 0xdeadbeefUL;
	p = duk_get_buffer_data(ctx, -1, &sz);
	if (p) {
		printf("p is not NULL, sz=%ld\n", (long) sz);
	} else {
		printf("p is NULL\n");
	}

	printf("final top: %ld\n", (long) duk_get_top(ctx));
	return 0;
}

/*===
*** test_invalid_index (duk_safe_call)
p is NULL
final top: 0
==> rc=0, result='undefined'
===*/

static duk_ret_t test_invalid_index(duk_context *ctx, void *udata) {
	unsigned char *p;
	duk_size_t sz;

	(void) udata;

	sz = (duk_size_t) 0xdeadbeefUL;
	p = duk_get_buffer_data(ctx, -1, &sz);
	if (p) {
		printf("p is not NULL, sz=%ld\n", (long) sz);
	} else {
		printf("p is NULL\n");
	}

	printf("final top: %ld\n", (long) duk_get_top(ctx));
	return 0;
}

void test(duk_context *ctx) {
	TEST_SAFE_CALL(test_basic);
	TEST_SAFE_CALL(test_null_ptr);
	TEST_SAFE_CALL(test_slice);
	TEST_SAFE_CALL(test_uncovered_buffer);
	TEST_SAFE_CALL(test_invalid_index);
}