The Tor Browser: modules/libjar/nsZipArchive.h@b8a032363ba2 (annotated)

modules/libjar/nsZipArchive.h@b8a032363ba2 (annotated)

modules/libjar/nsZipArchive.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* This Source Code Form is subject to the terms of the Mozilla Public
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 #ifndef nsZipArchive_h_
 #define nsZipArchive_h_
 #include "mozilla/Attributes.h"
 #define ZIP_TABSIZE   256
 #define ZIP_BUFLEN    (4*1024)      /* Used as output buffer when deflating items to a file */
 #include "plarena.h"
 #include "zlib.h"
 #include "zipstruct.h"
 #include "nsAutoPtr.h"
 #include "nsIFile.h"
 #include "nsISupportsImpl.h" // For mozilla::ThreadSafeAutoRefCnt
 #include "mozilla/FileUtils.h"
 #include "mozilla/FileLocation.h"
 #if defined(XP_WIN) && defined(_MSC_VER)
 #define MOZ_WIN_MEM_TRY_BEGIN __try {
 #define MOZ_WIN_MEM_TRY_CATCH(cmd) }                                \
   __except(GetExceptionCode()==EXCEPTION_IN_PAGE_ERROR ?            \
            EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH)   \
   {                                                                 \
     NS_WARNING("EXCEPTION_IN_PAGE_ERROR in " __FUNCTION__);         \
     cmd;                                                            \
   }
 #else
 #define MOZ_WIN_MEM_TRY_BEGIN {
 #define MOZ_WIN_MEM_TRY_CATCH(cmd) }
 #endif
 class nsZipFind;
 struct PRFileDesc;
 /**
  * This file defines some of the basic structures used by libjar to
  * read Zip files. It makes use of zlib in order to do the decompression.
  *
  * A few notes on the classes/structs:
  * nsZipArchive   represents a single Zip file, and maintains an index
  *                of all the items in the file.
  * nsZipItem      represents a single item (file) in the Zip archive.
  * nsZipFind      represents the metadata involved in doing a search,
  *                and current state of the iteration of found objects.
  * 'MT''safe' reading from the zipfile is performed through JARInputStream,
  * which maintains its own file descriptor, allowing for multiple reads
  * concurrently from the same zip file.
  */
 /**
  * nsZipItem -- a helper struct for nsZipArchive
  *
  * each nsZipItem represents one file in the archive and all the
  * information needed to manipulate it.
  */
 class nsZipItem
 {
 public:
   const char* Name() { return ((const char*)central) + ZIPCENTRAL_SIZE; }
   uint32_t LocalOffset();
   uint32_t Size();
   uint32_t RealSize();
   uint32_t CRC32();
   uint16_t Date();
   uint16_t Time();
   uint16_t Compression();
   bool     IsDirectory();
   uint16_t Mode();
   const uint8_t* GetExtraField(uint16_t aTag, uint16_t *aBlockSize);
   PRTime   LastModTime();
 #ifdef XP_UNIX
   bool     IsSymlink();
 #endif
   nsZipItem*         next;
   const ZipCentral*  central;
   uint16_t           nameLength;
   bool               isSynthetic;
 };
 class nsZipHandle;
 /**
  * nsZipArchive -- a class for reading the PKZIP file format.
  *
  */
 class nsZipArchive
 {
   friend class nsZipFind;
 public:
   /** constructing does not open the archive. See OpenArchive() */
   nsZipArchive();
   /** destructing the object closes the archive */
   ~nsZipArchive();
   /**
    * OpenArchive
    *
    * It's an error to call this more than once on the same nsZipArchive
    * object. If we were allowed to use exceptions this would have been
    * part of the constructor
    *
    * @param   aZipHandle  The nsZipHandle used to access the zip
    * @param   aFd         Optional PRFileDesc for Windows readahead optimization
    * @return  status code
    */
   nsresult OpenArchive(nsZipHandle *aZipHandle, PRFileDesc *aFd = nullptr);
   /**
    * OpenArchive
    *
    * Convenience function that generates nsZipHandle
    *
    * @param   aFile  The file used to access the zip
    * @return  status code
    */
   nsresult OpenArchive(nsIFile *aFile);
   /**
    * Test the integrity of items in this archive by running
    * a CRC check after extracting each item into a memory
    * buffer.  If an entry name is supplied only the
    * specified item is tested.  Else, if null is supplied
    * then all the items in the archive are tested.
    *
    * @return  status code
    */
   nsresult Test(const char *aEntryName);
   /**
    * Closes an open archive.
    */
   nsresult CloseArchive();
   /**
    * GetItem
    * @param   aEntryName Name of file in the archive
    * @return  pointer to nsZipItem
    */
   nsZipItem* GetItem(const char * aEntryName);
   /**
    * ExtractFile
    *
    * @param   zipEntry   Name of file in archive to extract
    * @param   outFD      Filedescriptor to write contents to
    * @param   outname    Name of file to write to
    * @return  status code
    */
   nsresult ExtractFile(nsZipItem * zipEntry, const char *outname, PRFileDesc * outFD);
   /**
    * FindInit
    *
    * Initializes a search for files in the archive. FindNext() returns
    * the actual matches. The nsZipFind must be deleted when you're done
    *
    * @param   aPattern    a string or RegExp pattern to search for
    *                      (may be nullptr to find all files in archive)
    * @param   aFind       a pointer to a pointer to a structure used
    *                      in FindNext.  In the case of an error this
    *                      will be set to nullptr.
    * @return  status code
    */
   nsresult FindInit(const char * aPattern, nsZipFind** aFind);
   /*
    * Gets an undependent handle to the mapped file.
    */
   nsZipHandle* GetFD();
   /**
    * Get pointer to the data of the item.
    * @param   aItem       Pointer to nsZipItem
    * reutrns null when zip file is corrupt.
    */
   const uint8_t* GetData(nsZipItem* aItem);
   bool GetComment(nsACString &aComment);
   /**
    * Gets the amount of memory taken up by the archive's mapping.
    * @return the size
    */
   int64_t SizeOfMapping();
   /*
    * Refcounting
    */
   NS_METHOD_(MozExternalRefCountType) AddRef(void);
   NS_METHOD_(MozExternalRefCountType) Release(void);
 private:
   //--- private members ---
   mozilla::ThreadSafeAutoRefCnt mRefCnt; /* ref count */
   NS_DECL_OWNINGTHREAD
   nsZipItem*    mFiles[ZIP_TABSIZE];
   PLArenaPool   mArena;
   const char*   mCommentPtr;
   uint16_t      mCommentLen;
   // Whether we synthesized the directory entries
   bool          mBuiltSynthetics;
   // file handle
   nsRefPtr<nsZipHandle> mFd;
   // file URI, for logging
   nsCString mURI;
 private:
   //--- private methods ---
   nsZipItem*        CreateZipItem();
   nsresult          BuildFileList(PRFileDesc *aFd = nullptr);
   nsresult          BuildSynthetics();
   nsZipArchive& operator=(const nsZipArchive& rhs) MOZ_DELETE;
   nsZipArchive(const nsZipArchive& rhs) MOZ_DELETE;
 };
 /**
  * nsZipFind
  *
  * a helper class for nsZipArchive, representing a search
  */
 class nsZipFind
 {
 public:
   nsZipFind(nsZipArchive* aZip, char* aPattern, bool regExp);
   ~nsZipFind();
   nsresult      FindNext(const char** aResult, uint16_t* aNameLen);
 private:
   nsRefPtr<nsZipArchive> mArchive;
   char*         mPattern;
   nsZipItem*    mItem;
   uint16_t      mSlot;
   bool          mRegExp;
   nsZipFind& operator=(const nsZipFind& rhs) MOZ_DELETE;
   nsZipFind(const nsZipFind& rhs) MOZ_DELETE;
 };
 /**
  * nsZipCursor -- a low-level class for reading the individual items in a zip.
  */
 class nsZipCursor {
 public:
   /**
    * Initializes the cursor
    *
    * @param   aItem       Item of interest
    * @param   aZip        Archive
    * @param   aBuf        Buffer used for decompression.
    *                      This determines the maximum Read() size in the compressed case.
    * @param   aBufSize    Buffer size
    * @param   doCRC       When set to true Read() will check crc
    */
   nsZipCursor(nsZipItem *aItem, nsZipArchive *aZip, uint8_t* aBuf = nullptr, uint32_t aBufSize = 0, bool doCRC = false);
   ~nsZipCursor();
   /**
    * Performs reads. In the compressed case it uses aBuf(passed in constructor), for stored files
    * it returns a zero-copy buffer.
    *
    * @param   aBytesRead  Outparam for number of bytes read.
    * @return  data read or nullptr if item is corrupted.
    */
   uint8_t* Read(uint32_t *aBytesRead) {
     return ReadOrCopy(aBytesRead, false);
   }
   /**
    * Performs a copy. It always uses aBuf(passed in constructor).
    *
    * @param   aBytesRead  Outparam for number of bytes read.
    * @return  data read or nullptr if item is corrupted.
    */
   uint8_t* Copy(uint32_t *aBytesRead) {
     return ReadOrCopy(aBytesRead, true);
   }
 private:
   /* Actual implementation for both Read and Copy above */
   uint8_t* ReadOrCopy(uint32_t *aBytesRead, bool aCopy);
   nsZipItem *mItem;
   uint8_t  *mBuf;
   uint32_t  mBufSize;
   z_stream  mZs;
   uint32_t mCRC;
   bool mDoCRC;
 };
 /**
  * nsZipItemPtr - a RAII convenience class for reading the individual items in a zip.
  * It reads whole files and does zero-copy IO for stored files. A buffer is allocated
  * for decompression.
  * Do not use when the file may be very large.
  */
 class nsZipItemPtr_base {
 public:
   /**
    * Initializes the reader
    *
    * @param   aZip        Archive
    * @param   aEntryName  Archive membername
    * @param   doCRC       When set to true Read() will check crc
    */
   nsZipItemPtr_base(nsZipArchive *aZip, const char *aEntryName, bool doCRC);
   uint32_t Length() const {
     return mReadlen;
   }
 protected:
   nsRefPtr<nsZipHandle> mZipHandle;
   nsAutoArrayPtr<uint8_t> mAutoBuf;
   uint8_t *mReturnBuf;
   uint32_t mReadlen;
 };
 template <class T>
 class nsZipItemPtr : public nsZipItemPtr_base {
 public:
   nsZipItemPtr(nsZipArchive *aZip, const char *aEntryName, bool doCRC = false) : nsZipItemPtr_base(aZip, aEntryName, doCRC) { }
   /**
    * @return buffer containing the whole zip member or nullptr on error.
    * The returned buffer is owned by nsZipItemReader.
    */
   const T* Buffer() const {
     return (const T*)mReturnBuf;
   }
   operator const T*() const {
     return Buffer();
   }
   /**
    * Relinquish ownership of zip member if compressed.
    * Copy member into a new buffer if uncompressed.
    * @return a buffer with whole zip member. It is caller's responsibility to free() it.
    */
   T* Forget() {
     if (!mReturnBuf)
       return nullptr;
     // In uncompressed mmap case, give up buffer
     if (mAutoBuf.get() == mReturnBuf) {
       mReturnBuf = nullptr;
       return (T*) mAutoBuf.forget();
     }
     T *ret = (T*) malloc(Length());
     memcpy(ret, mReturnBuf, Length());
     mReturnBuf = nullptr;
     return ret;
   }
 };
 class nsZipHandle {
 friend class nsZipArchive;
 friend class mozilla::FileLocation;
 public:
   static nsresult Init(nsIFile *file, nsZipHandle **ret,
                        PRFileDesc **aFd = nullptr);
   static nsresult Init(nsZipArchive *zip, const char *entry,
                        nsZipHandle **ret);
   NS_METHOD_(MozExternalRefCountType) AddRef(void);
   NS_METHOD_(MozExternalRefCountType) Release(void);
   int64_t SizeOfMapping();
 protected:
   const uint8_t * mFileData; /* pointer to mmaped file */
   uint32_t        mLen;      /* length of file and memory mapped area */
   mozilla::FileLocation mFile; /* source file if any, for logging */
 private:
   nsZipHandle();
   ~nsZipHandle();
   PRFileMap *                       mMap;    /* nspr datastructure for mmap */
   nsAutoPtr<nsZipItemPtr<uint8_t> > mBuf;
   mozilla::ThreadSafeAutoRefCnt     mRefCnt; /* ref count */
   NS_DECL_OWNINGTHREAD
 };
 nsresult gZlibInit(z_stream *zs);
 #endif /* nsZipArchive_h_ */

The Tor Browser / annotate

modules/libjar/nsZipArchive.h@b8a032363ba2 (annotated)

modules/libjar/nsZipArchive.h