Add an API to unpack Zip files directly from and to file descriptors.

chrome/common/zip_reader.h

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROME_COMMON_ZIP_READER_H_
 #define CHROME_COMMON_ZIP_READER_H_
 #pragma once
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
+#include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
 #include "third_party/zlib/contrib/minizip/unzip.h"
 
 namespace zip {
 
 // This class is used for reading zip files. A typical use case of this
 // class is to scan entries in a zip file and extract them. The code will
 // look like:
 //
@@ skipping 47 matching lines @@
     DISALLOW_COPY_AND_ASSIGN(EntryInfo);
   };
 
   ZipReader();
   ~ZipReader();
 
   // Opens the zip file specified by |zip_file_path|. Returns true on
   // success.
   bool Open(const FilePath& zip_file_path);
 
+#if defined(OS_POSIX)
+  // Opens the zip file referred to by the file descriptor |zip_fd|.
+  // Returns true on success.
+  bool OpenFromFd(int zip_fd);
+#endif
+
   // Closes the currently opened zip file. This function is called in the
   // destructor of the class, so you usually don't need to call this.
   void Close();
 
   // Returns true if there is at least one entry to read. This function is
   // used to scan entries with AdvanceToNextEntry(), like:
   //
   // while (reader.HasMore()) {
   //   // Do something with the current file here.
   //   reader.AdvanceToNextEntry();
@@ skipping 28 matching lines @@
   // Extracts the current entry to the given output directory path using
   // ExtractCurrentEntryToFilePath(). Sub directories are created as needed
   // based on the file path of the current entry. For example, if the file
   // path in zip is "foo/bar.txt", and the output directory is "output",
   // "output/foo/bar.txt" will be created.
   //
   // Returns true on success. OpenCurrentEntryInZip() must be called
   // beforehand.
   bool ExtractCurrentEntryIntoDirectory(const FilePath& output_directory_path);
 
+#if defined(OS_POSIX)
+  // Extracts the current entry by writing directly to a file descriptor.
+  // Does not close the file descriptor. Returns true on success.
+  bool ExtractCurrentEntryToFd(int fd);
+#endif
+
   // Returns the current entry info. Returns NULL if the current entry is
   // not yet opened. OpenCurrentEntryInZip() must be called beforehand.
   EntryInfo* current_entry_info() const {
     return current_entry_info_.get();
   }
 
   // Returns the number of entries in the zip file.
   // Open() must be called beforehand.
   int num_entries() const { return num_entries_; }
 
  private:
+  // Common code used both in Open and OpenFromFd.
+  bool OpenInternal();
+
   // Resets the internal state.
   void Reset();
 
   unzFile zip_file_;
   int num_entries_;
   bool reached_end_;
   scoped_ptr<EntryInfo> current_entry_info_;
 
   DISALLOW_COPY_AND_ASSIGN(ZipReader);
 };
 
 }  // namespace zip
 
 #endif  // CHROME_COMMON_ZIP_READER_H_