56 lines
1.8 KiB
C
56 lines
1.8 KiB
C
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#include <c_BufferInputStream.h>
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typedef struct {
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c_InStream_t base;
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const char* data;
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c_size_t size;
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c_size_t ptr;
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c_Allocator_t allocator;
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} c_BufferInImpl_t;
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static c_err_t _BufferIn_Read(c_InStream_t* self, void* buf, c_size_t len, c_size_t* bytes_read) {
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c_BufferInImpl_t* impl = (c_BufferInImpl_t*)self;
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if (!buf || len == 0) return C_ERR_PARAM;
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if (impl->ptr >= impl->size) {
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if (bytes_read) *bytes_read = 0;
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return C_ERR_OUTOFBOUND;
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}
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c_size_t available = impl->size - impl->ptr;
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c_size_t to_copy = (len < available) ? len : available;
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memcpy(buf, impl->data + impl->ptr, to_copy);
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impl->ptr += to_copy;
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if (bytes_read) *bytes_read = to_copy;
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return (to_copy == len) ? C_SUCCESS : C_ERR_OUTOFBOUND;
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}
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static void _BufferIn_Destroy(c_InStream_t* self) {
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c_BufferInImpl_t* impl = (c_BufferInImpl_t*)self;
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c_Allocator_t alloc = impl->allocator;
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c_Allocator_Free(&alloc, impl);
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}
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static const c_InStreamVtbl_t g_BufferInVtbl = { _BufferIn_Read, _BufferIn_Destroy };
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/* ------------------------------------------------------------------------------------------------------------------ */
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/* */
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c_err_t c_BufferInputStream_Create(c_InStream_t** out_stream, const void* buffer_ptr, c_size_t buffer_len, c_Allocator_t* allocator) {
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if (!out_stream || !buffer_ptr || buffer_len == 0) return C_ERR_PARAM;
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c_Allocator_t alloc = allocator ? *allocator : c_DefaultAllocator;
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c_BufferInImpl_t* impl = (c_BufferInImpl_t*)c_Allocator_Calloc(&alloc, 1, sizeof(c_BufferInImpl_t));
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if (!impl) return C_ERR_NOMEM;
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impl->base.vtbl = &g_BufferInVtbl;
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impl->data = (const char*)buffer_ptr;
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impl->size = buffer_len;
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impl->ptr = 0;
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impl->allocator = alloc;
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*out_stream = &impl->base;
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return C_SUCCESS;
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}
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