dolphin/Source/Core/Common/Src/LinearDiskCache.cpp

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// Copyright (C) 2003 Dolphin Project.
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, version 2.0.
// 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 General Public License 2.0 for more details.
// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/
// Official SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
#include "LinearDiskCache.h"
static const char ID[4] = {'D', 'C', 'A', 'C'};
// Update this to the current SVN revision every time you change shader generation code.
// We don't automatically get this from SVN_REV because that would mean regenerating the
// shader cache for every revision, graphics-related or not, which is simply annoying.
const int version = 5597;
LinearDiskCache::LinearDiskCache()
: file_(NULL), num_entries_(0) {
}
void LinearDiskCache::WriteHeader() {
fwrite(ID, 4, 1, file_);
fwrite(&version, 4, 1, file_);
}
bool LinearDiskCache::ValidateHeader() {
char header_id[4];
int header_version;
fread(&header_id, 4, 1, file_);
fread(&header_version, 4, 1, file_);
if (memcmp(header_id, ID, 4) != 0)
return false;
if (header_version != version)
return false;
return true;
}
int LinearDiskCache::OpenAndRead(const char *filename, LinearDiskCacheReader *reader) {
int items_read_count = 0;
file_ = fopen(filename, "rb");
int file_size = 0;
if (file_) {
fseek(file_, 0, SEEK_END);
file_size = (int)ftell(file_);
}
bool file_corrupt = false;
if (file_size == 0) {
if (file_)
fclose(file_);
// Reopen for writing.
file_ = fopen(filename, "wb");
// Cache empty, let's initialize a header.
WriteHeader();
num_entries_ = 0;
} else {
// file_ must be != 0 here.
// Back to the start we go.
fseek(file_, 0, SEEK_SET);
// Check that the file is valid
if (!ValidateHeader()) {
// Not valid - delete the file and start over.
fclose(file_);
unlink(filename);
// PanicAlert("LinearDiskCache file header broken.");
file_ = fopen(filename, "wb");
WriteHeader();
num_entries_ = 0;
} else {
// Valid - blow through it.
// We're past the header already thanks to ValidateHeader.
while (!feof(file_)) {
int key_size, value_size;
size_t key_size_size = fread(&key_size, 1, sizeof(key_size), file_);
size_t value_size_size = fread(&value_size, 1, sizeof(value_size), file_);
if (key_size_size == 0 && value_size_size == 0) {
// I guess feof isn't doing it's job - we're at the end.
break;
}
if (key_size <= 0 || value_size < 0 || key_size_size != 4 || value_size_size != 4) {
// PanicAlert("Disk cache file %s corrupted/truncated! ks: %i vs %i kss %i vss %i", filename,
// key_size, value_size, key_size_size, value_size_size);
file_corrupt = true;
break;
}
u8 *key = new u8[key_size];
u8 *value = new u8[value_size];
int actual_key_size = (int)fread(key, 1, key_size, file_);
int actual_value_size = (int)fread(value, 1, value_size, file_);
if (actual_key_size != key_size || actual_value_size != value_size) {
// PanicAlert("Disk cache file %s corrupted/truncated! ks: %i actual ks: %i vs: %i actual vs: %i", filename,
// key_size, actual_key_size, value_size, actual_value_size);
file_corrupt = true;
} else {
reader->Read(key, key_size, value, value_size);
items_read_count++;
}
delete [] key;
delete [] value;
}
fclose(file_);
// Done reading.
// Reopen file for append.
// At this point, ftell() will be at the end of the file,
// which happens to be exactly what we want.
file_ = fopen(filename, "ab");
fseek(file_, 0, SEEK_END);
}
}
if (file_corrupt) {
// Restore sanity, start over.
fclose(file_);
unlink(filename);
file_ = fopen(filename, "wb+");
WriteHeader();
}
return items_read_count;
}
void LinearDiskCache::Append(
const u8 *key, int key_size, const u8 *value, int value_size) {
// Should do a check that we don't already have "key"?
fwrite(&key_size, 1, sizeof(key_size), file_);
fwrite(&value_size, 1, sizeof(value_size), file_);
fwrite(key, 1, key_size, file_);
fwrite(value, 1, value_size, file_);
}
void LinearDiskCache::Sync() {
fflush(file_);
}
void LinearDiskCache::Close() {
fclose(file_);
file_ = 0;
num_entries_ = 0;
}