New Zip::ZipFromMemory API.

third_party/zlib/google/zip_internal.cc

Index: third_party/zlib/google/zip_internal.cc
diff --git a/third_party/zlib/google/zip_internal.cc b/third_party/zlib/google/zip_internal.cc
index a01ae8cea6f52cf9cf3e9d222e42220733b1bf63..e1ac2a00330a3fda1a5ab8eeeaad2a9042fd6018 100644
--- a/third_party/zlib/google/zip_internal.cc
+++ b/third_party/zlib/google/zip_internal.cc
@@ -2,12 +2,14 @@
 // 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 "third_party/zlib/google/zip_internal.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/time/time.h"
+#include "third_party/zlib/google/zip_reader.h"
 
 #if defined(USE_SYSTEM_MINIZIP)
 #include <minizip/ioapi.h>
@@ -230,6 +232,171 @@ int GetErrorOfZipBuffer(void* /*opaque*/, void* /*stream*/) {
   return 0;
 }
 
+// Returns a zip_fileinfo struct with the time represented by |file_time|.
+zip_fileinfo TimeToZipFileInfo(const base::Time& file_time) {
+  base::Time::Exploded file_time_parts;
+  file_time.LocalExplode(&file_time_parts);
+
+  zip_fileinfo zip_info = {};
+  if (file_time_parts.year >= 1980) {
+    // This if check works around the handling of the year value in
+    // contrib/minizip/zip.c in function zip64local_TmzDateToDosDate
+    // It assumes that dates below 1980 are in the double digit format.
+    // Hence the fail safe option is to leave the date unset. Some programs
+    // might show the unset date as 1980-0-0 which is invalid.
+    zip_info.tmz_date.tm_year = file_time_parts.year;
+    zip_info.tmz_date.tm_mon = file_time_parts.month - 1;
+    zip_info.tmz_date.tm_mday = file_time_parts.day_of_month;
+    zip_info.tmz_date.tm_hour = file_time_parts.hour;
+    zip_info.tmz_date.tm_min = file_time_parts.minute;
+    zip_info.tmz_date.tm_sec = file_time_parts.second;
+  }
+
+  return zip_info;
+}
+
+// Tells if there is at least one file in the |zip_path| archive which also
+// exists in |contents|.
+// Returns false if there was a problem opening the zip file.
+// The result of whether there is an intersection between the paths in
+// |zip_path| and |contents| is stored in |has_files|.
+bool HasFileInZip(const base::FilePath& zip_path,
+                  const zip::internal::ZipContents& contents,
+                  bool* has_files) {
+  DCHECK(has_files);
+  *has_files = false;
+
+  zip::ZipReader reader;
+  if (!reader.Open(zip_path)) {
+    DLOG(ERROR) << "Can't open zip file '" << zip_path.value();
+    return false;
+  }
+
+  for (zip::internal::ZipContents::const_iterator itr = contents.begin();
+       itr != contents.end(); ++itr)
+    if (reader.LocateAndOpenEntry(itr->first)) {
+      *has_files = true;
+      return true;
+    }
+
+  return true;
+}
+
+// Validates the contents in a zip::ZipContents to be used by ZipFromMemory:
+// Makes sure that all paths are relative and safe. Verifies that folders do not
+// have data (such would perhaps be a bug when utilizing the API).
+bool ValidateZipContents(const zip::internal::ZipContents& contents) {
+  for (zip::internal::ZipContents::const_iterator itr = contents.begin();
+       itr != contents.end(); ++itr) {
+    if (itr->first.empty() ||
+        itr->first.IsAbsolute() ||
+        itr->first.ReferencesParent()) {
+      DLOG(ERROR) << "Invalid file path '" << itr->first.value() << "'";
+      return false;
+    }
+    if (itr->first.EndsWithSeparator() &&
+        itr->second.size() != 0) {
+      // Can be NULL (remove) or 0-byte (add).
+      DLOG(ERROR) << "Folder must have empty contents '" <<
+          itr->first.value() << "'";
+      return false;
+    }
+  }
+  return true;
+}
+
+// Appends contents to the currently open zip entry in |zip_file|
+bool AddMemContentsToZip(zipFile zip_file,
+                         const base::FilePath& file_path,
+                         const void* contents,
+                         const size_t contents_length) {
+  if (contents_length != 0 &&
+      ZIP_OK != zipWriteInFileInZip(
+          zip_file, contents, contents_length)) {
+    DCHECK(contents);
+    DLOG(ERROR) << "Could not write data to zip for path "
+                << file_path.value();
+    return false;
+  }
+
+  return true;
+}
+
+// Creates a new file or folder entry in |zip_file| with |path| as the file
+// path and |contents| as the file contents. If |path| ends with a separator
+// it is considered to be a folder entry. Returns false in case of error.
+bool AddEntryToZipFromMemory(zipFile zip_file,
+                             const base::FilePath& path,
+                             const void* contents,
+                             const size_t contents_length) {
+  DCHECK(!path.IsAbsolute());
+  std::string str_path = path.AsUTF8Unsafe();
+#if defined(OS_WIN)
+  ReplaceSubstringsAfterOffset(&str_path, 0u, "\\", "/");
+#endif
+
+  zip_fileinfo file_info = TimeToZipFileInfo(base::Time::Now());
+  if (!zip::internal::ZipOpenNewFileInZipWrapper(
+           zip_file, str_path, &file_info))
+    return false;
+
+  bool success = true;
+  if (!path.EndsWithSeparator()) {
+    // Not a folder.
+    success = AddMemContentsToZip(zip_file, path, contents, contents_length);
+  }
+
+  if (ZIP_OK != zipCloseFileInZip(zip_file)) {
+    DLOG(ERROR) << "Could not close zip file entry " << str_path;
+    return false;
+  }
+
+  return success;
+}
+
+// Finds all files (path and contents) present in |zip_path| which are not
+// present in |contents| and adds them to |output_zip_file|
+// The function returns false in case of error handling the zip file.
+bool CopyZipContentsNotInMap(const base::FilePath& zip_path,
+                             const zip::internal::ZipContents& contents,
+                             zipFile output_zip_file) {
+  // Arbitrary big size, but not that big, of the maximum amount of memory this
+  // function can use to load a file's contents into memory.
+  const int64 max_allowed_file_size = 128 * 1024 * 1024;
+
+  zip::ZipReader reader;
+  if (!reader.Open(zip_path)) {
+    DLOG(ERROR) << "Can't open zip file '" << zip_path.value();
+    return false;
+  }
+
+  while (reader.HasMore()) {
+    if (!reader.OpenCurrentEntryInZip()) {
+      DLOG(ERROR) << "Can't open entry in zip file '" << zip_path.value();
+      return false;
+    }
+
+    zip::ZipReader::EntryInfo* entry = reader.current_entry_info();
+    DCHECK(entry);
+    if (contents.find(entry->file_path()) == contents.end()) {
+      std::string mem;
+      if (!reader.ExtractCurrentEntryToString(
+               max_allowed_file_size, &mem)) {
+        DLOG(ERROR) << "Failed to read contents of "
+                    << entry->file_path().value();
+        return false;
+      }
+      if (!AddEntryToZipFromMemory(
+               output_zip_file, entry->file_path(), mem.c_str(), mem.size()))
+        return false;
+    }
+    reader.AdvanceToNextEntry();
+  }
+  reader.Close();
+
+  return true;
+}
+
 }  // namespace
 
 namespace zip {
@@ -266,7 +433,7 @@ unzFile OpenHandleForUnzipping(HANDLE zip_handle) {
 #endif
 
 // static
-unzFile PreprareMemoryForUnzipping(const std::string& data) {
+unzFile PrepareMemoryForUnzipping(const std::string& data) {
   if (data.empty())
     return NULL;
 
@@ -312,5 +479,134 @@ zipFile OpenFdForZipping(int zip_fd, int append_flag) {
 }
 #endif
 
+zip_fileinfo GetFileInfoForZipping(const base::FilePath& path) {
+  base::Time file_time;
+  base::File::Info file_info;
+  if (base::GetFileInfo(path, &file_info))
+    file_time = file_info.last_modified;
+  return TimeToZipFileInfo(file_time);
+}
+
+bool ZipOpenNewFileInZipWrapper(zipFile zip_file,
+                                const std::string& str_path,
+                                const zip_fileinfo* file_info) {
+  // Section 4.4.4 http://www.pkware.com/documents/casestudies/APPNOTE.TXT
+  // Setting the Language encoding flag so the file is told to be in utf-8.
+  const uLong LANGUAGE_ENCODING_FLAG = 0x1 << 11;
+
+  if (ZIP_OK != zipOpenNewFileInZip4(
+                    zip_file,  // file
+                    str_path.c_str(),  // filename
+                    file_info,  // zipfi
+                    NULL,  // extrafield_local,
+                    0u,  // size_extrafield_local
+                    NULL,  // extrafield_global
+                    0u,  // size_extrafield_global
+                    NULL,  // comment
+                    Z_DEFLATED,  // method
+                    Z_DEFAULT_COMPRESSION,  // level
+                    0,  // raw
+                    -MAX_WBITS,  // windowBits
+                    DEF_MEM_LEVEL,  // memLevel
+                    Z_DEFAULT_STRATEGY,  // strategy
+                    NULL,  // password
+                    0,  // crcForCrypting
+                    0,  // versionMadeBy
+                    LANGUAGE_ENCODING_FLAG)) {  // flagBase
+    DLOG(ERROR) << "Could not open zip file entry " << str_path;
+    return false;
+  }
+  return true;
+}
+
+bool ZipFromMemory(const base::FilePath& zip_path,
+                   const ZipContents& contents,
+                   bool append) {
+
+  // There is really no point in calling this with no input, and
+  // there are simpler ways to create a 0 byte file.
+  if (contents.size() == 0)
+    return true;
+
+  CHECK(!zip_path.empty());
+  // This check saves us having to worry with invalid input after.
+  CHECK(ValidateZipContents(contents));
+
+  int64 file_size = 0;
+  if (append &&
+      (!base::PathExists(zip_path) ||
+       (base::GetFileSize(zip_path, &file_size) && file_size < 1))) {
+    // If the size is 0, this might be a new temporary file.
+    append = false;
+  }
+
+  // The path to the zip path that will actually be used to write the new data.
+  base::FilePath zip_path_used = zip_path;
+
+  bool has_intersection = false;
+  if (append) {
+    // NOTE: zipOpenNewFileInZip4 is not clever enough to replace files,
+    // therefore this has to explicitly create a new file and reinsert the
+    // data we want without duplications, which is what the minizip headers
+    // tell to do.
+    if (!HasFileInZip(zip_path, contents, &has_intersection))
+      return false;
+
+    if (has_intersection) {
+      append = false;
+      if (!base::CreateTemporaryFile(&zip_path_used)) {
+        DLOG(WARNING) << "Couldn't create temporary file for "
+                      << zip_path.value();
+        return false;
+      }
+    }
+  }
+
+  zipFile zip_file = internal::OpenForZipping(
+      zip_path_used.AsUTF8Unsafe(),
+      append ? APPEND_STATUS_ADDINZIP : APPEND_STATUS_CREATE);
+  if (!zip_file) {
+    DLOG(WARNING) << "Couldn't create file " << zip_path_used.value();
+    return false;
+  }
+
+  bool success = true;
+
+  if (has_intersection) {
+    // There was an intersection. There are files in the old archive with
+    // same paths as found in |contents| therefore the old ones need to be
+    // replaced.
+    success = CopyZipContentsNotInMap(zip_path, contents, zip_file);
+  }
+
+  for (ZipContents::const_iterator itr = contents.begin();
+       itr != contents.end() && success;
+       ++itr) {
+    if (itr->second.data() != NULL) {
+      success = AddEntryToZipFromMemory(
+          zip_file, itr->first, itr->second.data(), itr->second.size());
+    }
+  }
+
+  if (ZIP_OK != zipClose(zip_file, NULL)) {
+    DLOG(ERROR) << "Error closing zip file " << zip_path_used.value();
+    success = false;
+  }
+
+  if (zip_path_used != zip_path) {
+    if (success) {
+      if (!base::Move(zip_path_used, zip_path)) {
+        base::DeleteFile(zip_path_used, false);
+        DLOG(ERROR) << "Error moving zip file " << zip_path_used.value();
+        return false;
+      }
+    } else {
+      base::DeleteFile(zip_path_used, false);
+    }
+  }
+
+  return success;
+}
+
 }  // namespace internal
 }  // namespace zip