/*
* BufFileRead
*
* Like fread() except we assume 1-byte element size.
*/
size_t
BufFileRead(BufFile *file, void *ptr, size_t size)
{
size_t nread = 0;
size_t nthistime;
if (file->dirty)
{
if (BufFileFlush(file) != 0)
return 0; /* could not flush... */
Assert(!file->dirty);
}
while (size > 0)
{
if (file->pos >= file->nbytes)
{
/* Try to load more data into buffer. */
file->curOffset += file->pos;
file->pos = 0;
file->nbytes = 0;
BufFileLoadBuffer(file);
if (file->nbytes <= 0)
break; /* no more data available */
}
nthistime = file->nbytes - file->pos;
if (nthistime > size)
nthistime = size;
Assert(nthistime > 0);
memcpy(ptr, file->buffer + file->pos, nthistime);
file->pos += nthistime;
ptr = (void *) ((char *) ptr + nthistime);
size -= nthistime;
nread += nthistime;
}
return nread;
}
/*
* BufFileRead
*
* Like fread() except we assume 1-byte element size.
*/
Size
BufFileRead(BufFile *file, void *ptr, Size size)
{
size_t nread = 0;
int nthistime;
if (file->dirty)
BufFileFlush(file);
while (size > 0)
{
if (file->pos >= file->nbytes)
{
Assert(file->pos == file->nbytes);
file->offset += file->pos;
file->pos = 0;
file->nbytes = 0;
/*
* Read full blocks directly into caller's buffer.
*/
while (size >= BLCKSZ)
{
size_t nwant;
nwant = size - size % BLCKSZ;
nthistime = BufFileLoadBuffer(file, ptr, nwant);
file->offset += nthistime;
ptr = (char *) ptr + nthistime;
size -= nthistime;
nread += nthistime;
if (size == 0 || nthistime == 0)
{
return nread;
}
}
/* Try to load more data into buffer. */
file->nbytes = BufFileLoadBuffer(file, file->buffer, BLCKSZ);
if (file->nbytes == 0)
{
break; /* no more data available */
}
}
nthistime = file->nbytes - file->pos;
if (nthistime > size)
{
nthistime = (int) size;
}
Assert(nthistime > 0);
memcpy(ptr, file->buffer + file->pos, nthistime);
file->pos += nthistime;
ptr = (void *) ((char *) ptr + nthistime);
size -= nthistime;
nread += nthistime;
}
return nread;
}
