encfs/fs/MemFileIO.cpp
2013-01-29 03:07:54 +00:00

107 lines
2.5 KiB
C++

/*****************************************************************************
* Author: Valient Gough <vgough@pobox.com>
*
*****************************************************************************
* Copyright (c) 2012 Valient Gough
*
* This program is free software: you can redistribute it and/or modify it under
* the terms of the GNU Lesser General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option) any
* later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
* FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
* details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "fs/MemFileIO.h"
#include "base/Error.h"
#include <glog/logging.h>
static Interface MemFileIO_iface = makeInterface("FileIO/Mem", 1, 0, 0);
MemFileIO* NewMemFileIO(const Interface& iface) {
(void)iface;
return new MemFileIO(0);
}
MemFileIO::MemFileIO(int size)
: writable(false) {
buf.resize(size);
}
MemFileIO::~MemFileIO() {
}
Interface MemFileIO::interface() const {
return MemFileIO_iface;
}
void MemFileIO::setFileName(const char *name) {
this->name = name;
}
const char *MemFileIO::getFileName() const {
return name.c_str();
}
int MemFileIO::open(int flags) {
bool requestWrite = ((flags & O_RDWR) || (flags & O_WRONLY));
writable = writable || requestWrite;
LOG(ERROR) << "returning fake file descriptor";
return 0;
}
int MemFileIO::getAttr(struct stat* stbuf) const {
stbuf->st_size = buf.size();
return 0;
}
off_t MemFileIO::getSize() const {
return buf.size();
}
ssize_t MemFileIO::read(const IORequest& req) const {
rAssert(req.offset >= 0);
int len = req.dataLen;
if (req.offset + req.dataLen > getSize()) {
len = getSize() - req.offset;
}
if (len < 0) {
len = 0;
}
memcpy(req.data, &buf[req.offset], len);
return len;
}
bool MemFileIO::write(const IORequest& req) {
rAssert(req.offset >= 0);
if (req.offset + req.dataLen > getSize()) {
truncate(req.offset + req.dataLen);
}
rAssert(req.offset + req.dataLen <= getSize());
memcpy(&buf[req.offset], req.data, req.dataLen);
return true;
}
int MemFileIO::truncate(off_t size) {
buf.resize(size);
return 0;
}
bool MemFileIO::isWritable() const {
return writable;
}