1 // 2 // Copyright 2011 The Android Open Source Project 3 // 4 // Implementation file for CrunchCache 5 // This file defines functions laid out and documented in 6 // CrunchCache.h 7 8 #include <utils/Vector.h> 9 #include <utils/String8.h> 10 11 #include "DirectoryWalker.h" 12 #include "FileFinder.h" 13 #include "CacheUpdater.h" 14 #include "CrunchCache.h" 15 16 using namespace android; 17 18 CrunchCache::CrunchCache(String8 sourcePath, String8 destPath, FileFinder* ff) 19 : mSourcePath(sourcePath), mDestPath(destPath), mSourceFiles(0), mDestFiles(0), mFileFinder(ff) 20 { 21 // We initialize the default value to return to 0 so if a file doesn't exist 22 // then all files are automatically "newer" than it. 23 24 // Set file extensions to look for. Right now just pngs. 25 mExtensions.push(String8(".png")); 26 27 // Load files into our data members 28 loadFiles(); 29 } 30 31 size_t CrunchCache::crunch(CacheUpdater* cu, bool forceOverwrite) 32 { 33 size_t numFilesUpdated = 0; 34 35 // Iterate through the source files and compare to cache. 36 // After processing a file, remove it from the source files and 37 // from the dest files. 38 // We're done when we're out of files in source. 39 String8 relativePath; 40 while (mSourceFiles.size() > 0) { 41 // Get the full path to the source file, then convert to a c-string 42 // and offset our beginning pointer to the length of the sourcePath 43 // This efficiently strips the source directory prefix from our path. 44 // Also, String8 doesn't have a substring method so this is what we've 45 // got to work with. 46 const char* rPathPtr = mSourceFiles.keyAt(0).string()+mSourcePath.length(); 47 // Strip leading slash if present 48 int offset = 0; 49 if (rPathPtr[0] == OS_PATH_SEPARATOR) 50 offset = 1; 51 relativePath = String8(rPathPtr + offset); 52 53 if (forceOverwrite || needsUpdating(relativePath)) { 54 cu->processImage(mSourcePath.appendPathCopy(relativePath), 55 mDestPath.appendPathCopy(relativePath)); 56 numFilesUpdated++; 57 // crunchFile(relativePath); 58 } 59 // Delete this file from the source files and (if it exists) from the 60 // dest files. 61 mSourceFiles.removeItemsAt(0); 62 mDestFiles.removeItem(mDestPath.appendPathCopy(relativePath)); 63 } 64 65 // Iterate through what's left of destFiles and delete leftovers 66 while (mDestFiles.size() > 0) { 67 cu->deleteFile(mDestFiles.keyAt(0)); 68 mDestFiles.removeItemsAt(0); 69 } 70 71 // Update our knowledge of the files cache 72 // both source and dest should be empty by now. 73 loadFiles(); 74 75 return numFilesUpdated; 76 } 77 78 void CrunchCache::loadFiles() 79 { 80 // Clear out our data structures to avoid putting in duplicates 81 mSourceFiles.clear(); 82 mDestFiles.clear(); 83 84 // Make a directory walker that points to the system. 85 DirectoryWalker* dw = new SystemDirectoryWalker(); 86 87 // Load files in the source directory 88 mFileFinder->findFiles(mSourcePath, mExtensions, mSourceFiles,dw); 89 90 // Load files in the destination directory 91 mFileFinder->findFiles(mDestPath,mExtensions,mDestFiles,dw); 92 93 delete dw; 94 } 95 96 bool CrunchCache::needsUpdating(String8 relativePath) const 97 { 98 // Retrieve modification dates for this file entry under the source and 99 // cache directory trees. The vectors will return a modification date of 0 100 // if the file doesn't exist. 101 time_t sourceDate = mSourceFiles.valueFor(mSourcePath.appendPathCopy(relativePath)); 102 time_t destDate = mDestFiles.valueFor(mDestPath.appendPathCopy(relativePath)); 103 return sourceDate > destDate; 104 }