blob: 269caf1b0112fb18e62e1eb29ae3b69e7b520fa3 [file] [log] [blame]
// Copyright 2014 The Chromium OS 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 <string>
#include "archive.h"
// Defines a reader for archive volumes. This class is used by libarchive
// for custom reads:
class VolumeReader {
virtual ~VolumeReader() {}
// Tries to read bytes_to_read from the archive. The result will be stored at
// *destination_buffer, which is the address of a buffer handled by
// VolumeReaderJavaScriptStream. *destination_buffer must be available until
// the next VolumeReader:Read call or until VolumeReader is destructed.
// The operation must be synchronous (libarchive requirement), so it
// should NOT be done on the main thread. bytes_to_read should be > 0.
// Returns the actual number of read bytes or ARCHIVE_FATAL in case of
// failure.
virtual int64_t Read(int64_t bytes_to_read,
const void** destination_buffer) = 0;
// Tries to skip bytes_to_skip number of bytes. Returns the actual number of
// skipped bytes or 0 if none were skipped. In case of failure
// VolumeReader::Skip returns 0 bytes and VolumeReader::Read can be used
// to skip those bytes by discarding them.
virtual int64_t Skip(int64_t bytes_to_skip) = 0;
// Tries to seek to offset from whence. Returns the resulting offset location
// or ARCHIVE_FATAL in case of errors. Similar to
virtual int64_t Seek(int64_t offset, int whence) = 0;
// Fetches a passphrase for reading. If the passphrase is not available it
// returns NULL.
virtual const char* Passphrase() = 0;
#endif // VOLUME_READER_H_