Permalink
Switch branches/tags
Nothing to show
Find file
Fetching contributors…
Cannot retrieve contributors at this time
68 lines (53 sloc) 1.74 KB
#include "local_gridfile.h"
#include <algorithm>
using namespace std;
int LocalGridFile::write(const char *buf, size_t nbyte, off_t offset)
{
int last_chunk = (offset + nbyte) / _chunkSize;
int written = 0;
while(last_chunk > _chunks.size() - 1) {
char *new_buf = new char[_chunkSize];
memset(new_buf, 0, _chunkSize);
_chunks.push_back(new_buf);
}
int chunk_num = offset / _chunkSize;
char* dest_buf = _chunks[chunk_num];
int buf_offset = offset % _chunkSize;
if(buf_offset) {
dest_buf += offset % _chunkSize;
int to_write = min<size_t>(nbyte - written,
(long unsigned int)(_chunkSize - buf_offset));
memcpy(dest_buf, buf, to_write);
written += to_write;
chunk_num++;
}
while(written < nbyte) {
dest_buf = _chunks[chunk_num];
int to_write = min<size_t>(nbyte - written,
(long unsigned int)_chunkSize);
memcpy(dest_buf, buf, to_write);
written += to_write;
chunk_num++;
}
_length = max(_length, (int)offset + written);
_dirty = true;
return written;
}
int LocalGridFile::read(char* buf, size_t size, off_t offset)
{
size_t len = 0;
int chunk_num = offset / _chunkSize;
while(len < size && chunk_num < _chunks.size()) {
const char* chunk = _chunks[chunk_num];
size_t to_read = min<size_t>((size_t)_chunkSize, size - len);
if(!len && offset) {
chunk += offset % _chunkSize;
to_read = min<size_t>(to_read,
(size_t)(_chunkSize - (offset % _chunkSize)));
}
memcpy(buf + len, chunk, to_read);
len += to_read;
chunk_num++;
}
return len;
}