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//
// Copyright 2011 The Android Open Source Project
//
// Implementation file for CrunchCache
// This file defines functions laid out and documented in
// CrunchCache.h
#include <utils/Compat.h>
#include <utils/Vector.h>
#include <utils/String8.h>
#include "DirectoryWalker.h"
#include "FileFinder.h"
#include "CacheUpdater.h"
#include "CrunchCache.h"
using namespace android;
CrunchCache::CrunchCache(String8 sourcePath, String8 destPath, FileFinder* ff)
: mSourcePath(sourcePath), mDestPath(destPath), mSourceFiles(0), mDestFiles(0), mFileFinder(ff)
{
// We initialize the default value to return to 0 so if a file doesn't exist
// then all files are automatically "newer" than it.
// Set file extensions to look for. Right now just pngs.
mExtensions.push(String8(".png"));
// Load files into our data members
loadFiles();
}
size_t CrunchCache::crunch(CacheUpdater* cu, bool forceOverwrite)
{
size_t numFilesUpdated = 0;
// Iterate through the source files and compare to cache.
// After processing a file, remove it from the source files and
// from the dest files.
// We're done when we're out of files in source.
String8 relativePath;
while (mSourceFiles.size() > 0) {
// Get the full path to the source file, then convert to a c-string
// and offset our beginning pointer to the length of the sourcePath
// This efficiently strips the source directory prefix from our path.
// Also, String8 doesn't have a substring method so this is what we've
// got to work with.
const char* rPathPtr = mSourceFiles.keyAt(0).string()+mSourcePath.length();
// Strip leading slash if present
int offset = 0;
if (rPathPtr[0] == OS_PATH_SEPARATOR)
offset = 1;
relativePath = String8(rPathPtr + offset);
if (forceOverwrite || needsUpdating(relativePath)) {
cu->processImage(mSourcePath.appendPathCopy(relativePath),
mDestPath.appendPathCopy(relativePath));
numFilesUpdated++;
// crunchFile(relativePath);
}
// Delete this file from the source files and (if it exists) from the
// dest files.
mSourceFiles.removeItemsAt(0);
mDestFiles.removeItem(mDestPath.appendPathCopy(relativePath));
}
// Iterate through what's left of destFiles and delete leftovers
while (mDestFiles.size() > 0) {
cu->deleteFile(mDestFiles.keyAt(0));
mDestFiles.removeItemsAt(0);
}
// Update our knowledge of the files cache
// both source and dest should be empty by now.
loadFiles();
return numFilesUpdated;
}
void CrunchCache::loadFiles()
{
// Clear out our data structures to avoid putting in duplicates
mSourceFiles.clear();
mDestFiles.clear();
// Make a directory walker that points to the system.
DirectoryWalker* dw = new SystemDirectoryWalker();
// Load files in the source directory
mFileFinder->findFiles(mSourcePath, mExtensions, mSourceFiles,dw);
// Load files in the destination directory
mFileFinder->findFiles(mDestPath,mExtensions,mDestFiles,dw);
delete dw;
}
bool CrunchCache::needsUpdating(String8 relativePath) const
{
// Retrieve modification dates for this file entry under the source and
// cache directory trees. The vectors will return a modification date of 0
// if the file doesn't exist.
time_t sourceDate = mSourceFiles.valueFor(mSourcePath.appendPathCopy(relativePath));
time_t destDate = mDestFiles.valueFor(mDestPath.appendPathCopy(relativePath));
return sourceDate > destDate;
}