Android: Access to files from APK is boosted

Open APK file just once and cache a file list information (name and
position inside archive). Also a general ZipFile helper class is
created to read multiple files from Zip archives - might be used
for another platforms if needed.

Previously it was so for each separate file access operation:
- Open zip archive, initially parse its structure (unzOpen)
- Locate the particular file there by a linear search through
  full archive (unzLocateFile).
  So if file does not exist - still an archive has to be handled
  fully, even slower than a file exists.
- Read file.
- Close zip archive

After this commit:
- Once - open zip/apk file and collect file list information
  (average consumed time - the same like a search for 2 different
  files by unzLocateFile)
- When needed - directly retrieve file position inside the archive,
  setting it up to the zip reader and reading file

ZipFile class is located in support/zip_support/ZipUtils.h and .cpp
to prevent creation of a new files and adding them to multiple
project files.

cocos2dx/platform/android/CCFileUtils.cpp

@@ -24,6 +24,7 @@ THE SOFTWARE.
 
 #define __CC_PLATFORM_FILEUTILS_CPP__
 #include "platform/CCFileUtilsCommon_cpp.h"
+#include "support/zip_support/ZipUtils.h"
 
 using namespace std;
 
@@ -36,6 +37,7 @@ NS_CC_BEGIN
 static string s_strResourcePath = "";
     
 static CCFileUtils* s_pFileUtils = NULL;
+static ZipFile *s_pZipFile = NULL;
 
 CCFileUtils* CCFileUtils::sharedFileUtils()
 {
@@ -43,6 +45,7 @@ CCFileUtils* CCFileUtils::sharedFileUtils()
     {
         s_pFileUtils = new CCFileUtils();
         s_strResourcePath = getApkPath();
+        s_pZipFile = new ZipFile(s_strResourcePath, "assets/");
     }
     return s_pFileUtils;
 }
@@ -94,13 +97,13 @@ unsigned char* CCFileUtils::getFileData(const char* pszFileName, const char* psz
         
         fullPath.insert(0, m_obDirectory.c_str());
         fullPath.insert(0, "assets/");
-        pData =  CCFileUtils::getFileDataFromZip(s_strResourcePath.c_str(), fullPath.c_str(), pSize);
+        pData = s_pZipFile->getFileData(fullPath, pSize);
         
         if (! pData && m_obDirectory.size() > 0)
         {
             // search from root
             pathWithoutDirectory.insert(0, "assets/");
-            pData =  CCFileUtils::getFileDataFromZip(s_strResourcePath.c_str(), pathWithoutDirectory.c_str(), pSize);
+            pData = s_pZipFile->getFileData(pathWithoutDirectory, pSize);
         }
     }
     else

cocos2dx/support/zip_support/ZipUtils.cpp

@@ -28,9 +28,13 @@ THE SOFTWARE.
 #include "ZipUtils.h"
 #include "ccMacros.h"
 #include "platform/CCFileUtils.h"
+#include "unzip.h"
+#include <map>
 
 NS_CC_BEGIN
 
+// --------------------- ZipUtils ---------------------
+
 // memory in iPhone is precious
 // Should buffer factor be 1.5 instead of 2 ?
 #define BUFFER_INC_FACTOR (2)
@@ -280,4 +284,139 @@ int ZipUtils::ccInflateCCZFile(const char *path, unsigned char **out)
      return len;
 }
 
+// --------------------- ZipFile ---------------------
+// from unzip.cpp
+#define UNZ_MAXFILENAMEINZIP 256
+
+class ZipFilePrivate
+{
+public:
+    unzFile zipFile;
+
+    // std::unordered_map is faster if available on the platform
+    typedef std::map<std::string, unz_file_pos> FileListContainer;
+    FileListContainer fileList;
+};
+
+ZipFile::ZipFile(const std::string &zipFile, const std::string &filter)
+    : m_data(new ZipFilePrivate)
+{
+    m_data->zipFile = unzOpen(zipFile.c_str());
+    if (m_data->zipFile)
+    {
+        setFilter(filter);
+    }
+}
+
+ZipFile::~ZipFile()
+{
+    if (m_data && m_data->zipFile)
+    {
+        unzClose(m_data->zipFile);
+    }
+    CC_SAFE_DELETE(m_data);
+}
+
+bool ZipFile::setFilter(const std::string &filter)
+{
+    bool ret = false;
+    do
+    {
+        CC_BREAK_IF(!m_data);
+        CC_BREAK_IF(!m_data->zipFile);
+
+        // clear existing file list
+        m_data->fileList.clear();
+
+        // go through all files and store position information about the required files
+        int err = unzGoToFirstFile(m_data->zipFile);
+        while (err == UNZ_OK)
+        {
+            unz_file_pos posInfo;
+            int posErr = unzGetFilePos(m_data->zipFile, &posInfo);
+            if (posErr == UNZ_OK)
+            {
+                // UNZ_MAXFILENAMEINZIP + 1 - it is done so in unzLocateFile
+                char szCurrentFileName[UNZ_MAXFILENAMEINZIP + 1];
+                int nameErr = unzGetCurrentFileInfo64(m_data->zipFile, NULL,
+                        szCurrentFileName, sizeof(szCurrentFileName) - 1,
+                        NULL, 0, NULL, 0);
+                std::string currentFileName = szCurrentFileName;
+                if (nameErr == UNZ_OK)
+                {
+                    // cache info about filtered files only (like 'assets/')
+                    if (filter.empty()
+                        || currentFileName.substr(0, filter.length()) == filter)
+                    {
+                        m_data->fileList[currentFileName] = posInfo;
+                    }
+                }
+            }
+            err = unzGoToNextFile(m_data->zipFile);
+        }
+        ret = true;
+
+    } while(false);
+
+    return ret;
+}
+
+bool ZipFile::fileExists(const std::string &fileName) const
+{
+    bool ret = false;
+    do
+    {
+        CC_BREAK_IF(!m_data);
+
+        ret = m_data->fileList.find(fileName) != m_data->fileList.end();
+    } while(false);
+
+    return ret;
+}
+
+unsigned char *ZipFile::getFileData(const std::string &fileName, unsigned long *pSize)
+{
+    unsigned char * pBuffer = NULL;
+    if (pSize)
+    {
+        *pSize = 0;
+    }
+
+    do
+    {
+        CC_BREAK_IF(!m_data->zipFile);
+        CC_BREAK_IF(fileName.empty());
+
+        ZipFilePrivate::FileListContainer::const_iterator it = m_data->fileList.find(fileName);
+        CC_BREAK_IF(it ==  m_data->fileList.end());
+
+        unz_file_pos filePos = it->second;
+
+        int nRet = unzGoToFilePos(m_data->zipFile, &filePos);
+        CC_BREAK_IF(UNZ_OK != nRet);
+
+        char szFilePathA[UNZ_MAXFILENAMEINZIP + 1];
+        unz_file_info FileInfo;
+        nRet = unzGetCurrentFileInfo(m_data->zipFile, &FileInfo,
+                szFilePathA, sizeof(szFilePathA) - 1, NULL, 0, NULL, 0);
+        CC_BREAK_IF(UNZ_OK != nRet);
+
+        nRet = unzOpenCurrentFile(m_data->zipFile);
+        CC_BREAK_IF(UNZ_OK != nRet);
+
+        pBuffer = new unsigned char[FileInfo.uncompressed_size];
+        int nSize = 0;
+        nSize = unzReadCurrentFile(m_data->zipFile, pBuffer, FileInfo.uncompressed_size);
+        CCAssert(nSize == 0 || nSize == (int)FileInfo.uncompressed_size, "the file size is wrong");
+
+        if (pSize)
+        {
+            *pSize = FileInfo.uncompressed_size;
+        }
+        unzCloseCurrentFile(m_data->zipFile);
+    } while (0);
+
+    return pBuffer;
+}
+
 NS_CC_END

cocos2dx/support/zip_support/ZipUtils.h

@@ -24,6 +24,8 @@ THE SOFTWARE.
 #ifndef __SUPPORT_ZIPUTILS_H__
 #define __SUPPORT_ZIPUTILS_H__
 
+#include <string>
+
 namespace cocos2d
 {
     /* XXX: pragma pack ??? */
@@ -91,6 +93,68 @@ namespace cocos2d
             unsigned int outLenghtHint);
     };
 
-} // end of namespace cocos2d
-#endif // __PLATFORM_WOPHONE_ZIPUTILS_H__
+    // forward declaration
+    class ZipFilePrivate;
+
+    /**
+    * Zip file - reader helper class.
+    *
+    * It will cache the file list of a particular zip file with positions inside an archive,
+    * so it would be much faster to read some particular files or to check their existance.
+    *
+    * @since v2.0.5
+    */
+    class ZipFile
+    {
+    public:
+        /**
+        * Constructor, open zip file and store file list.
+        *
+        * @param zipFile Zip file name
+        * @param filter The first part of file names, which should be accessible.
+        *               For example, "assets/". Other files will be missed.
+        *
+        * @since v2.0.5
+        */
+        ZipFile(const std::string &zipFile, const std::string &filter = std::string());
+        virtual ~ZipFile();
+
+        /**
+        * Regenerate accessible file list based on a new filter string.
+        *
+        * @param filter New filter string (first part of files names)
+        * @return true whenever zip file is open successfully and it is possible to locate
+        *              at least the first file, false otherwise
+        *
+        * @since v2.0.5
+        */
+        bool setFilter(const std::string &filter);
+
+        /**
+        * Check does a file exists or not in zip file
+        *
+        * @param fileName File to be checked on existance
+        * @return true whenever file exists, false otherwise
+        *
+        * @since v2.0.5
+        */
+        bool fileExists(const std::string &fileName) const;
+
+        /**
+        * Get resource file data from a zip file.
+        * @param fileName File name
+        * @param[out] pSize If the file read operation succeeds, it will be the data size, otherwise 0.
+        * @return Upon success, a pointer to the data is returned, otherwise NULL.
+        * @warning Recall: you are responsible for calling delete[] on any Non-NULL pointer returned.
+        *
+        * @since v2.0.5
+        */
+        unsigned char *getFileData(const std::string &fileName, unsigned long *pSize);
+
+    private:
+        /** Internal data like zip file pointer / file list array and so on */
+        ZipFilePrivate *m_data;
+    };
+} // end of namespace cocos2d
+#endif // __SUPPORT_ZIPUTILS_H__