zchunk_t *
zfile_read (zfile_t *self, size_t bytes, off_t offset)
{
assert (self);
assert (self->handle);
self->eof = false;
// Calculate real number of bytes to read
if (offset > self->cursize) {
// if we tried to read 'after' the cursise, then we are at the end
bytes = 0;
self->eof = true;
}
else
if (bytes > (size_t) (self->cursize - offset)) {
// if we are trying to read more than there is, we are at the end
self->eof = true;
bytes = (size_t) (self->cursize - offset);
}
if (fseek (self->handle, (long) offset, SEEK_SET) == -1) {
return NULL;
}
return zchunk_read (self->handle, bytes);
}
zchunk_t *
zchunk_slurp (const char *filename, size_t maxsize)
{
size_t size = zsys_file_size (filename);
if ((ssize_t) size == -1)
return NULL;
if (size > maxsize && maxsize != 0)
size = maxsize;
FILE *handle = fopen (filename, "r");
zchunk_t *chunk = zchunk_read (handle, size);
assert (chunk);
fclose (handle);
return chunk;
}
zchunk_t *
zfile_read (zfile_t *self, size_t bytes, off_t offset)
{
assert (self);
assert (self->handle);
// Calculate real number of bytes to read
if (offset > self->cursize)
bytes = 0;
else if (bytes > (size_t) (self->cursize - offset))
bytes = (size_t) (self->cursize - offset);
if (fseek (self->handle, (long) offset, SEEK_SET) == -1)
return NULL;
self->eof = false;
zchunk_t *chunk = zchunk_read (self->handle, bytes);
if (chunk)
self->eof = zchunk_size (chunk) < bytes;
return chunk;
}
///
// Read chunk from an open file descriptor
QZchunk * QZchunk::read (FILE *handle, size_t bytes)
{
QZchunk *rv = new QZchunk (zchunk_read (handle, bytes));
return rv;
}