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42 lines
1.4 KiB
42 lines
1.4 KiB
name: duk_get_buffer
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proto: |
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void *duk_get_buffer(duk_context *ctx, duk_idx_t idx, duk_size_t *out_size);
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stack: |
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[ ... val! ... ]
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summary: |
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<p>Get the data pointer for a (plain) buffer value at <code>idx</code> without
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modifying or coercing the value. Returns a non-<code>NULL</code> pointer if the value
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is a valid buffer with a non-zero size. For a zero-size buffer, may return a
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<code>NULL</code> or a non-<code>NULL</code> pointer. Returns <code>NULL</code>
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if the value is not a buffer or the index is invalid. If <code>out_size</code> is
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non-<code>NULL</code>, the size of the buffer is written to <code>*out_size</code>; 0
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is written if the return value is <code>NULL</code>.</p>
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<p>If the target value is a fixed buffer, the returned pointer is stable and
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won't change during the lifetime of the buffer. For dynamic and external
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buffers the pointer may change as the buffer is resized or reconfigured;
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the caller is responsible for ensuring pointer values returned from this API
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call are not used after the buffer is resized/reconfigured.</p>
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<div include="buffer-null-pointer-ambiguity.html" />
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example: |
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void *ptr;
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duk_size_t sz;
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ptr = duk_get_buffer(ctx, -3, &sz);
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printf("buf=%p, size=%lu\n", ptr, (unsigned long) sz);
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tags:
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- stack
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- buffer
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seealso:
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- duk_require_buffer
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- duk_get_buffer_data
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- duk_require_buffer_data
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introduced: 1.0.0
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