Mesen-S/SevenZip/7zMemBuffer.c

53 lines
1.4 KiB
C

#include "Precomp.h"
#include "7zMemBuffer.h"
#include <memory.h>
WRes MemBuffer_Read(CSzMemBuffer *p, void *data, size_t *size)
{
size_t originalSize = *size;
if(originalSize == 0)
return 0;
size_t length = (size_t)(p->pos + (Int64)(*size) > p->size ? p->size - p->pos - 1 : *size);
memcpy(data, (char*)(p->buffer) + p->pos, length);
p->pos += length;
return 0;
}
WRes MemBuffer_Seek(CSzMemBuffer *p, Int64 *pos, ESzSeek origin)
{
switch(origin) {
case SZ_SEEK_SET: p->pos = 0 + *pos; break;
case SZ_SEEK_CUR: p->pos += *pos; break;
case SZ_SEEK_END: p->pos = p->size - *pos; break;
default: return 1;
}
*pos = p->pos;
return 0;
}
static SRes MemBufferInStream_Read(void *pp, void *buf, size_t *size)
{
CMemBufferInStream *p = (CMemBufferInStream *)pp;
return (MemBuffer_Read(&p->buffer, buf, size) == 0) ? SZ_OK : SZ_ERROR_READ;
}
static SRes MemBufferInStream_Seek(void *pp, Int64 *pos, ESzSeek origin)
{
CMemBufferInStream *p = (CMemBufferInStream *)pp;
return MemBuffer_Seek(&p->buffer, pos, origin);
}
void MemBufferInit(CMemBufferInStream *memBuferStream, CLookToRead *lookStream, void* buffer, size_t size)
{
memBuferStream->buffer.buffer = buffer;
memBuferStream->buffer.pos = 0;
memBuferStream->buffer.size = size;
memBuferStream->s.Read = MemBufferInStream_Read;
memBuferStream->s.Seek = MemBufferInStream_Seek;
LookToRead_CreateVTable(lookStream, False);
lookStream->realStream = &memBuferStream->s;
LookToRead_Init(lookStream);
}