Use base::File::Whence for VolumeArchive::Seek.

Better type safety, and helps minimise changes in the eventual minizip
uprev.

BUG=889703

Change-Id: Ie05f7fcf2d83d792326b728a0cb54d3a4b628b10
Reviewed-on: https://chromium-review.googlesource.com/c/1273996
Commit-Queue: Anand Mistry <amistry@chromium.org>
Reviewed-by: Luciano Pacheco <lucmult@chromium.org>
Cr-Commit-Position: refs/heads/master@{#598845}

chrome/browser/resources/chromeos/zip_archiver/cpp/volume_archive_minizip.cc

@@ -11,6 +11,7 @@
 #include <limits>
 #include <utility>
 
+#include "base/files/file.h"
 #include "base/strings/string_util.h"
 #include "base/time/time.h"
 #include "ppapi/cpp/logging.h"
@@ -73,7 +74,7 @@ void* CustomArchiveOpen(void* archive,
 int64_t DynamicCache(VolumeArchiveMinizip* archive, int64_t unzip_size) {
   int64_t offset = archive->reader()->offset();
   if (archive->reader()->Seek(static_cast<int64_t>(offset),
-                              ZLIB_FILEFUNC_SEEK_SET) < 0) {
+                              base::File::FROM_BEGIN) < 0) {
     return -1 /* Error */;
   }
 
@@ -98,7 +99,7 @@ int64_t DynamicCache(VolumeArchiveMinizip* archive, int64_t unzip_size) {
   } while (left_length > 0);
 
   if (archive->reader()->Seek(static_cast<int64_t>(offset),
-                              ZLIB_FILEFUNC_SEEK_SET) < 0) {
+                              base::File::FROM_BEGIN) < 0) {
     return -1 /* Error */;
   }
   archive->dynamic_cache_size_ = bytes_to_read - left_length;
@@ -122,7 +123,7 @@ uint32_t CustomArchiveRead(void* archive,
     memcpy(buffer, archive_minizip->static_cache_.get() + offset_in_cache,
            size);
     if (archive_minizip->reader()->Seek(static_cast<int64_t>(size),
-                                        ZLIB_FILEFUNC_SEEK_CUR) < 0) {
+                                        base::File::FROM_CURRENT) < 0) {
       return -1 /* Error */;
     }
     return size;
@@ -154,7 +155,7 @@ uint32_t CustomArchiveRead(void* archive,
     unzip_buffer_pointer += copy_length;
     left_length -= copy_length;
     if (archive_minizip->reader()->Seek(static_cast<int64_t>(copy_length),
-                                        ZLIB_FILEFUNC_SEEK_CUR) < 0) {
+                                        base::File::FROM_CURRENT) < 0) {
       return -1 /* Error */;
     }
   } while (left_length > 0);
@@ -182,8 +183,24 @@ long CustomArchiveSeek(void* archive,
   VolumeArchiveMinizip* archive_minizip =
       static_cast<VolumeArchiveMinizip*>(archive);
 
-  long return_value = static_cast<long>(archive_minizip->reader()->Seek(
-      static_cast<int64_t>(offset), static_cast<int64_t>(origin)));
+  base::File::Whence whence;
+  switch (origin) {
+    case ZLIB_FILEFUNC_SEEK_SET:
+      whence = base::File::FROM_BEGIN;
+      break;
+    case ZLIB_FILEFUNC_SEEK_CUR:
+      whence = base::File::FROM_CURRENT;
+      break;
+    case ZLIB_FILEFUNC_SEEK_END:
+      whence = base::File::FROM_END;
+      break;
+    default:
+      NOTREACHED();
+      return -1;
+  }
+
+  long return_value = static_cast<long>(
+      archive_minizip->reader()->Seek(static_cast<int64_t>(offset), whence));
   if (return_value >= 0)
     return 0 /* Success */;
   return -1 /* Error */;
@@ -251,7 +268,7 @@ bool VolumeArchiveMinizip::Init(const std::string& encoding) {
   int64_t left_length = static_cache_size_;
   static_cache_offset_ = std::max(reader()->archive_size() - static_cache_size_,
                                   static_cast<int64_t>(0));
-  if (reader()->Seek(static_cache_offset_, ZLIB_FILEFUNC_SEEK_SET) < 0) {
+  if (reader()->Seek(static_cache_offset_, base::File::FROM_BEGIN) < 0) {
     set_error_message(kArchiveOpenError);
     return false /* Error */;
   }
@@ -264,7 +281,7 @@ bool VolumeArchiveMinizip::Init(const std::string& encoding) {
   } while (left_length > 0);
 
   // Set the offset to the original position.
-  if (reader()->Seek(previous_offset, ZLIB_FILEFUNC_SEEK_SET) < 0) {
+  if (reader()->Seek(previous_offset, base::File::FROM_BEGIN) < 0) {
     set_error_message(kArchiveOpenError);
     return false /* Error */;
   }

chrome/browser/resources/chromeos/zip_archiver/cpp/volume_reader.h

@@ -9,6 +9,8 @@
 #include <memory>
 #include <string>
 
+#include "base/files/file.h"
+
 // Defines a reader for archive volumes. This class is used by minizip
 // for custom reads.
 class VolumeReader {
@@ -30,7 +32,7 @@ class VolumeReader {
   // Tries to seek to offset from whence. Returns the resulting offset location
   // or -1 in case of errors. Similar to
   // http://www.cplusplus.com/reference/cstdio/fseek/
-  virtual int64_t Seek(int64_t offset, int whence) = 0;
+  virtual int64_t Seek(int64_t offset, base::File::Whence whence) = 0;
 
   // Fetches a passphrase for reading. If the passphrase is not available it
   // returns nullptr.

chrome/browser/resources/chromeos/zip_archiver/cpp/volume_reader_javascript_stream.cc

@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <limits>
 
+#include "base/files/file.h"
 #include "chrome/browser/resources/chromeos/zip_archiver/cpp/javascript_requestor_interface.h"
 #include "ppapi/cpp/logging.h"
 #include "third_party/minizip/src/unzip.h"
@@ -177,18 +178,19 @@ int64_t VolumeReaderJavaScriptStream::Read(int64_t bytes_to_read,
   return bytes_read;
 }
 
-int64_t VolumeReaderJavaScriptStream::Seek(int64_t offset, int whence) {
+int64_t VolumeReaderJavaScriptStream::Seek(int64_t offset,
+                                           base::File::Whence whence) {
   base::AutoLock al(shared_state_lock_);
 
   int64_t new_offset = offset_;
   switch (whence) {
-    case ZLIB_FILEFUNC_SEEK_SET:
+    case base::File::FROM_BEGIN:
       new_offset = offset;
       break;
-    case ZLIB_FILEFUNC_SEEK_CUR:
+    case base::File::FROM_CURRENT:
       new_offset += offset;
       break;
-    case ZLIB_FILEFUNC_SEEK_END:
+    case base::File::FROM_END:
       new_offset = archive_size_ + offset;
       break;
     default:

chrome/browser/resources/chromeos/zip_archiver/cpp/volume_reader_javascript_stream.h

@@ -63,7 +63,7 @@ class VolumeReaderJavaScriptStream : public VolumeReader {
   int64_t Read(int64_t bytes_to_read, const void** destination_buffer) override;
 
   // See volume_reader.h for description.
-  int64_t Seek(int64_t offset, int whence) override;
+  int64_t Seek(int64_t offset, base::File::Whence whence) override;
 
   // Sets the request Id to be used by the reader.
   void SetRequestId(const std::string& request_id);