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/Compat.h>
9 #include <utils/Vector.h>
10 #include <utils/String8.h>
11
12 #include "DirectoryWalker.h"
13 #include "FileFinder.h"
14 #include "CacheUpdater.h"
15 #include "CrunchCache.h"
16
17 using namespace android;
18
CrunchCache(String8 sourcePath,String8 destPath,FileFinder * ff)19 CrunchCache::CrunchCache(String8 sourcePath, String8 destPath, FileFinder* ff)
20 : mSourcePath(sourcePath), mDestPath(destPath), mSourceFiles(0), mDestFiles(0), mFileFinder(ff)
21 {
22 // We initialize the default value to return to 0 so if a file doesn't exist
23 // then all files are automatically "newer" than it.
24
25 // Set file extensions to look for. Right now just pngs.
26 mExtensions.push(String8(".png"));
27
28 // Load files into our data members
29 loadFiles();
30 }
31
crunch(CacheUpdater * cu,bool forceOverwrite)32 size_t CrunchCache::crunch(CacheUpdater* cu, bool forceOverwrite)
33 {
34 size_t numFilesUpdated = 0;
35
36 // Iterate through the source files and compare to cache.
37 // After processing a file, remove it from the source files and
38 // from the dest files.
39 // We're done when we're out of files in source.
40 String8 relativePath;
41 while (mSourceFiles.size() > 0) {
42 // Get the full path to the source file, then convert to a c-string
43 // and offset our beginning pointer to the length of the sourcePath
44 // This efficiently strips the source directory prefix from our path.
45 // Also, String8 doesn't have a substring method so this is what we've
46 // got to work with.
47 const char* rPathPtr = mSourceFiles.keyAt(0).string()+mSourcePath.length();
48 // Strip leading slash if present
49 int offset = 0;
50 if (rPathPtr[0] == OS_PATH_SEPARATOR)
51 offset = 1;
52 relativePath = String8(rPathPtr + offset);
53
54 if (forceOverwrite || needsUpdating(relativePath)) {
55 cu->processImage(mSourcePath.appendPathCopy(relativePath),
56 mDestPath.appendPathCopy(relativePath));
57 numFilesUpdated++;
58 // crunchFile(relativePath);
59 }
60 // Delete this file from the source files and (if it exists) from the
61 // dest files.
62 mSourceFiles.removeItemsAt(0);
63 mDestFiles.removeItem(mDestPath.appendPathCopy(relativePath));
64 }
65
66 // Iterate through what's left of destFiles and delete leftovers
67 while (mDestFiles.size() > 0) {
68 cu->deleteFile(mDestFiles.keyAt(0));
69 mDestFiles.removeItemsAt(0);
70 }
71
72 // Update our knowledge of the files cache
73 // both source and dest should be empty by now.
74 loadFiles();
75
76 return numFilesUpdated;
77 }
78
loadFiles()79 void CrunchCache::loadFiles()
80 {
81 // Clear out our data structures to avoid putting in duplicates
82 mSourceFiles.clear();
83 mDestFiles.clear();
84
85 // Make a directory walker that points to the system.
86 DirectoryWalker* dw = new SystemDirectoryWalker();
87
88 // Load files in the source directory
89 mFileFinder->findFiles(mSourcePath, mExtensions, mSourceFiles,dw);
90
91 // Load files in the destination directory
92 mFileFinder->findFiles(mDestPath,mExtensions,mDestFiles,dw);
93
94 delete dw;
95 }
96
needsUpdating(String8 relativePath) const97 bool CrunchCache::needsUpdating(String8 relativePath) const
98 {
99 // Retrieve modification dates for this file entry under the source and
100 // cache directory trees. The vectors will return a modification date of 0
101 // if the file doesn't exist.
102 time_t sourceDate = mSourceFiles.valueFor(mSourcePath.appendPathCopy(relativePath));
103 time_t destDate = mDestFiles.valueFor(mDestPath.appendPathCopy(relativePath));
104 return sourceDate > destDate;
105 }
106