OVMS3/OVMS.V3/components/duktape/src-input/duk_hbuffer_alloc.c

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/*
* duk_hbuffer allocation and freeing.
*/
#include "duk_internal.h"
/* Allocate a new duk_hbuffer of a certain type and return a pointer to it
* (NULL on error). Write buffer data pointer to 'out_bufdata' (only if
* allocation successful).
*/
DUK_INTERNAL duk_hbuffer *duk_hbuffer_alloc(duk_heap *heap, duk_size_t size, duk_small_uint_t flags, void **out_bufdata) {
duk_hbuffer *res = NULL;
duk_size_t header_size;
duk_size_t alloc_size;
DUK_ASSERT(heap != NULL);
DUK_ASSERT(out_bufdata != NULL);
DUK_DDD(DUK_DDDPRINT("allocate hbuffer"));
/* Size sanity check. Should not be necessary because caller is
* required to check this, but we don't want to cause a segfault
* if the size wraps either in duk_size_t computation or when
* storing the size in a 16-bit field.
*/
if (size > DUK_HBUFFER_MAX_BYTELEN) {
DUK_D(DUK_DPRINT("hbuffer alloc failed: size too large: %ld", (long) size));
return NULL; /* no need to write 'out_bufdata' */
}
if (flags & DUK_BUF_FLAG_EXTERNAL) {
header_size = sizeof(duk_hbuffer_external);
alloc_size = sizeof(duk_hbuffer_external);
} else if (flags & DUK_BUF_FLAG_DYNAMIC) {
header_size = sizeof(duk_hbuffer_dynamic);
alloc_size = sizeof(duk_hbuffer_dynamic);
} else {
header_size = sizeof(duk_hbuffer_fixed);
alloc_size = sizeof(duk_hbuffer_fixed) + size;
DUK_ASSERT(alloc_size >= sizeof(duk_hbuffer_fixed)); /* no wrapping */
}
res = (duk_hbuffer *) DUK_ALLOC(heap, alloc_size);
if (DUK_UNLIKELY(res == NULL)) {
goto alloc_error;
}
/* zero everything unless requested not to do so */
#if defined(DUK_USE_ZERO_BUFFER_DATA)
duk_memzero((void *) res,
(flags & DUK_BUF_FLAG_NOZERO) ? header_size : alloc_size);
#else
duk_memzero((void *) res, header_size);
#endif
if (flags & DUK_BUF_FLAG_EXTERNAL) {
duk_hbuffer_external *h;
h = (duk_hbuffer_external *) res;
DUK_UNREF(h);
*out_bufdata = NULL;
#if defined(DUK_USE_EXPLICIT_NULL_INIT)
#if defined(DUK_USE_HEAPPTR16)
/* the compressed pointer is zeroed which maps to NULL, so nothing to do. */
#else
DUK_HBUFFER_EXTERNAL_SET_DATA_PTR(heap, h, NULL);
#endif
#endif
DUK_ASSERT(DUK_HBUFFER_EXTERNAL_GET_DATA_PTR(heap, h) == NULL);
} else if (flags & DUK_BUF_FLAG_DYNAMIC) {
duk_hbuffer_dynamic *h = (duk_hbuffer_dynamic *) res;
void *ptr;
if (size > 0) {
DUK_ASSERT(!(flags & DUK_BUF_FLAG_EXTERNAL)); /* alloc external with size zero */
DUK_DDD(DUK_DDDPRINT("dynamic buffer with nonzero size, alloc actual buffer"));
#if defined(DUK_USE_ZERO_BUFFER_DATA)
ptr = DUK_ALLOC_ZEROED(heap, size);
#else
ptr = DUK_ALLOC(heap, size);
#endif
if (DUK_UNLIKELY(ptr == NULL)) {
/* Because size > 0, NULL check is correct */
goto alloc_error;
}
*out_bufdata = ptr;
DUK_HBUFFER_DYNAMIC_SET_DATA_PTR(heap, h, ptr);
} else {
*out_bufdata = NULL;
#if defined(DUK_USE_EXPLICIT_NULL_INIT)
#if defined(DUK_USE_HEAPPTR16)
/* the compressed pointer is zeroed which maps to NULL, so nothing to do. */
#else
DUK_HBUFFER_DYNAMIC_SET_DATA_PTR(heap, h, NULL);
#endif
#endif
DUK_ASSERT(DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(heap, h) == NULL);
}
} else {
*out_bufdata = (void *) ((duk_hbuffer_fixed *) (void *) res + 1);
}
DUK_HBUFFER_SET_SIZE(res, size);
DUK_HEAPHDR_SET_TYPE(&res->hdr, DUK_HTYPE_BUFFER);
if (flags & DUK_BUF_FLAG_DYNAMIC) {
DUK_HBUFFER_SET_DYNAMIC(res);
if (flags & DUK_BUF_FLAG_EXTERNAL) {
DUK_HBUFFER_SET_EXTERNAL(res);
}
} else {
DUK_ASSERT(!(flags & DUK_BUF_FLAG_EXTERNAL));
}
DUK_HEAP_INSERT_INTO_HEAP_ALLOCATED(heap, &res->hdr);
DUK_DDD(DUK_DDDPRINT("allocated hbuffer: %p", (void *) res));
return res;
alloc_error:
DUK_DD(DUK_DDPRINT("hbuffer allocation failed"));
DUK_FREE(heap, res);
return NULL; /* no need to write 'out_bufdata' */
}
/* For indirect allocs. */
DUK_INTERNAL void *duk_hbuffer_get_dynalloc_ptr(duk_heap *heap, void *ud) {
duk_hbuffer_dynamic *buf = (duk_hbuffer_dynamic *) ud;
DUK_UNREF(heap);
return (void *) DUK_HBUFFER_DYNAMIC_GET_DATA_PTR(heap, buf);
}