root/third_party/zlib/google/zip_internal.cc

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DEFINITIONS

This source file includes following definitions.
  1. ZipOpenFunc
  2. FdOpenFileFunc
  3. CloseFileFunc
  4. FillFdOpenFileFunc
  5. HandleOpenFileFunc
  6. OpenZipBuffer
  7. ReadZipBuffer
  8. WriteZipBuffer
  9. GetOffsetOfZipBuffer
  10. SeekZipBuffer
  11. CloseZipBuffer
  12. GetErrorOfZipBuffer
  13. OpenForUnzipping
  14. OpenFdForUnzipping
  15. OpenHandleForUnzipping
  16. PreprareMemoryForUnzipping
  17. OpenForZipping
  18. OpenFdForZipping

// 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.

#include "third_party/zlib/google/zip.h"

#include <algorithm>

#include "base/logging.h"
#include "base/strings/utf_string_conversions.h"

#if defined(USE_SYSTEM_MINIZIP)
#include <minizip/ioapi.h>
#include <minizip/unzip.h>
#include <minizip/zip.h>
#else
#include "third_party/zlib/contrib/minizip/unzip.h"
#include "third_party/zlib/contrib/minizip/zip.h"
#if defined(OS_WIN)
#include "third_party/zlib/contrib/minizip/iowin32.h"
#elif defined(OS_POSIX)
#include "third_party/zlib/contrib/minizip/ioapi.h"
#endif  // defined(OS_POSIX)
#endif  // defined(USE_SYSTEM_MINIZIP)

namespace {

#if defined(OS_WIN)
typedef struct {
  HANDLE hf;
  int error;
} WIN32FILE_IOWIN;

// This function is derived from third_party/minizip/iowin32.c.
// Its only difference is that it treats the char* as UTF8 and
// uses the Unicode version of CreateFile.
void* ZipOpenFunc(void *opaque, const char* filename, int mode) {
  DWORD desired_access, creation_disposition;
  DWORD share_mode, flags_and_attributes;
  HANDLE file = 0;
  void* ret = NULL;

  desired_access = share_mode = flags_and_attributes = 0;

  if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER) == ZLIB_FILEFUNC_MODE_READ) {
    desired_access = GENERIC_READ;
    creation_disposition = OPEN_EXISTING;
    share_mode = FILE_SHARE_READ;
  } else if (mode & ZLIB_FILEFUNC_MODE_EXISTING) {
    desired_access = GENERIC_WRITE | GENERIC_READ;
    creation_disposition = OPEN_EXISTING;
  } else if (mode & ZLIB_FILEFUNC_MODE_CREATE) {
    desired_access = GENERIC_WRITE | GENERIC_READ;
    creation_disposition = CREATE_ALWAYS;
  }

  base::string16 filename16 = base::UTF8ToUTF16(filename);
  if ((filename != NULL) && (desired_access != 0)) {
    file = CreateFile(filename16.c_str(), desired_access, share_mode,
        NULL, creation_disposition, flags_and_attributes, NULL);
  }

  if (file == INVALID_HANDLE_VALUE)
    file = NULL;

  if (file != NULL) {
    WIN32FILE_IOWIN file_ret;
    file_ret.hf = file;
    file_ret.error = 0;
    ret = malloc(sizeof(WIN32FILE_IOWIN));
    if (ret == NULL)
      CloseHandle(file);
    else
      *(static_cast<WIN32FILE_IOWIN*>(ret)) = file_ret;
  }
  return ret;
}
#endif

#if defined(OS_POSIX)
// Callback function for zlib that opens a file stream from a file descriptor.
void* FdOpenFileFunc(void* opaque, const char* filename, int mode) {
  FILE* file = NULL;
  const char* mode_fopen = NULL;

  if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER) == ZLIB_FILEFUNC_MODE_READ)
    mode_fopen = "rb";
  else if (mode & ZLIB_FILEFUNC_MODE_EXISTING)
    mode_fopen = "r+b";
  else if (mode & ZLIB_FILEFUNC_MODE_CREATE)
    mode_fopen = "wb";

  if ((filename != NULL) && (mode_fopen != NULL))
    file = fdopen(*static_cast<int*>(opaque), mode_fopen);

  return file;
}

// We don't actually close the file stream since that would close
// the underlying file descriptor, and we don't own it. However we do need to
// flush buffers and free |opaque| since we malloc'ed it in FillFdOpenFileFunc.
int CloseFileFunc(void* opaque, void* stream) {
  fflush(static_cast<FILE*>(stream));
  free(opaque);
  return 0;
}

// Fills |pzlib_filecunc_def| appropriately to handle the zip file
// referred to by |fd|.
void FillFdOpenFileFunc(zlib_filefunc_def* pzlib_filefunc_def, int fd) {
  fill_fopen_filefunc(pzlib_filefunc_def);
  pzlib_filefunc_def->zopen_file = FdOpenFileFunc;
  pzlib_filefunc_def->zclose_file = CloseFileFunc;
  int* ptr_fd = static_cast<int*>(malloc(sizeof(fd)));
  *ptr_fd = fd;
  pzlib_filefunc_def->opaque = ptr_fd;
}
#endif  // defined(OS_POSIX)

#if defined(OS_WIN)
// Callback function for zlib that opens a file stream from a Windows handle.
void* HandleOpenFileFunc(void* opaque, const char* filename, int mode) {
  WIN32FILE_IOWIN file_ret;
  file_ret.hf = static_cast<HANDLE>(opaque);
  file_ret.error = 0;
  if (file_ret.hf == INVALID_HANDLE_VALUE)
    return NULL;

  void* ret = malloc(sizeof(WIN32FILE_IOWIN));
  if (ret != NULL)
    *(static_cast<WIN32FILE_IOWIN*>(ret)) = file_ret;
  return ret;
}
#endif

// A struct that contains data required for zlib functions to extract files from
// a zip archive stored in memory directly. The following I/O API functions
// expect their opaque parameters refer to this struct.
struct ZipBuffer {
  const char* data;  // weak
  size_t length;
  size_t offset;
};

// Opens the specified file. When this function returns a non-NULL pointer, zlib
// uses this pointer as a stream parameter while compressing or uncompressing
// data. (Returning NULL represents an error.) This function initializes the
// given opaque parameter and returns it because this parameter stores all
// information needed for uncompressing data. (This function does not support
// writing compressed data and it returns NULL for this case.)
void* OpenZipBuffer(void* opaque, const char* /*filename*/, int mode) {
  if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER) != ZLIB_FILEFUNC_MODE_READ) {
    NOTREACHED();
    return NULL;
  }
  ZipBuffer* buffer = static_cast<ZipBuffer*>(opaque);
  if (!buffer || !buffer->data || !buffer->length)
    return NULL;
  buffer->offset = 0;
  return opaque;
}

// Reads compressed data from the specified stream. This function copies data
// refered by the opaque parameter and returns the size actually copied.
uLong ReadZipBuffer(void* opaque, void* /*stream*/, void* buf, uLong size) {
  ZipBuffer* buffer = static_cast<ZipBuffer*>(opaque);
  DCHECK_LE(buffer->offset, buffer->length);
  size_t remaining_bytes = buffer->length - buffer->offset;
  if (!buffer || !buffer->data || !remaining_bytes)
    return 0;
  size = std::min(size, static_cast<uLong>(remaining_bytes));
  memcpy(buf, &buffer->data[buffer->offset], size);
  buffer->offset += size;
  return size;
}

// Writes compressed data to the stream. This function always returns zero
// because this implementation is only for reading compressed data.
uLong WriteZipBuffer(void* /*opaque*/,
                     void* /*stream*/,
                     const void* /*buf*/,
                     uLong /*size*/) {
  NOTREACHED();
  return 0;
}

// Returns the offset from the beginning of the data.
long GetOffsetOfZipBuffer(void* opaque, void* /*stream*/) {
  ZipBuffer* buffer = static_cast<ZipBuffer*>(opaque);
  if (!buffer)
    return -1;
  return static_cast<long>(buffer->offset);
}

// Moves the current offset to the specified position.
long SeekZipBuffer(void* opaque, void* /*stream*/, uLong offset, int origin) {
  ZipBuffer* buffer = static_cast<ZipBuffer*>(opaque);
  if (!buffer)
    return -1;
  if (origin == ZLIB_FILEFUNC_SEEK_CUR) {
    buffer->offset = std::min(buffer->offset + static_cast<size_t>(offset),
                              buffer->length);
    return 0;
  }
  if (origin == ZLIB_FILEFUNC_SEEK_END) {
    buffer->offset = (buffer->length > offset) ? buffer->length - offset : 0;
    return 0;
  }
  if (origin == ZLIB_FILEFUNC_SEEK_SET) {
    buffer->offset = std::min(buffer->length, static_cast<size_t>(offset));
    return 0;
  }
  NOTREACHED();
  return -1;
}

// Closes the input offset and deletes all resources used for compressing or
// uncompressing data. This function deletes the ZipBuffer object referred by
// the opaque parameter since zlib deletes the unzFile object and it does not
// use this object any longer.
int CloseZipBuffer(void* opaque, void* /*stream*/) {
  if (opaque)
    free(opaque);
  return 0;
}

// Returns the last error happened when reading or writing data. This function
// always returns zero, which means there are not any errors.
int GetErrorOfZipBuffer(void* /*opaque*/, void* /*stream*/) {
  return 0;
}

}  // namespace

namespace zip {
namespace internal {

unzFile OpenForUnzipping(const std::string& file_name_utf8) {
  zlib_filefunc_def* zip_func_ptrs = NULL;
#if defined(OS_WIN)
  zlib_filefunc_def zip_funcs;
  fill_win32_filefunc(&zip_funcs);
  zip_funcs.zopen_file = ZipOpenFunc;
  zip_func_ptrs = &zip_funcs;
#endif
  return unzOpen2(file_name_utf8.c_str(), zip_func_ptrs);
}

#if defined(OS_POSIX)
unzFile OpenFdForUnzipping(int zip_fd) {
  zlib_filefunc_def zip_funcs;
  FillFdOpenFileFunc(&zip_funcs, zip_fd);
  // Passing dummy "fd" filename to zlib.
  return unzOpen2("fd", &zip_funcs);
}
#endif

#if defined(OS_WIN)
unzFile OpenHandleForUnzipping(HANDLE zip_handle) {
  zlib_filefunc_def zip_funcs;
  fill_win32_filefunc(&zip_funcs);
  zip_funcs.zopen_file = HandleOpenFileFunc;
  zip_funcs.opaque = zip_handle;
  return unzOpen2("fd", &zip_funcs);
}
#endif

// static
unzFile PreprareMemoryForUnzipping(const std::string& data) {
  if (data.empty())
    return NULL;

  ZipBuffer* buffer = static_cast<ZipBuffer*>(malloc(sizeof(ZipBuffer)));
  if (!buffer)
    return NULL;
  buffer->data = data.data();
  buffer->length = data.length();
  buffer->offset = 0;

  zlib_filefunc_def zip_functions;
  zip_functions.zopen_file = OpenZipBuffer;
  zip_functions.zread_file = ReadZipBuffer;
  zip_functions.zwrite_file = WriteZipBuffer;
  zip_functions.ztell_file = GetOffsetOfZipBuffer;
  zip_functions.zseek_file = SeekZipBuffer;
  zip_functions.zclose_file = CloseZipBuffer;
  zip_functions.zerror_file = GetErrorOfZipBuffer;
  zip_functions.opaque = static_cast<void*>(buffer);
  return unzOpen2(NULL, &zip_functions);
}

zipFile OpenForZipping(const std::string& file_name_utf8, int append_flag) {
  zlib_filefunc_def* zip_func_ptrs = NULL;
#if defined(OS_WIN)
  zlib_filefunc_def zip_funcs;
  fill_win32_filefunc(&zip_funcs);
  zip_funcs.zopen_file = ZipOpenFunc;
  zip_func_ptrs = &zip_funcs;
#endif
  return zipOpen2(file_name_utf8.c_str(),
                  append_flag,
                  NULL,  // global comment
                  zip_func_ptrs);
}

#if defined(OS_POSIX)
zipFile OpenFdForZipping(int zip_fd, int append_flag) {
  zlib_filefunc_def zip_funcs;
  FillFdOpenFileFunc(&zip_funcs, zip_fd);
  // Passing dummy "fd" filename to zlib.
  return zipOpen2("fd", append_flag, NULL, &zip_funcs);
}
#endif

}  // namespace internal
}  // namespace zip

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