tesseract/cube/cached_file.h

70 lines
1.9 KiB
C
Raw Normal View History

/**********************************************************************
* File: cached_file.h
* Description: Declaration of a Cached File class
* Author: Ahmad Abdulkader
* Created: 2007
*
* (C) Copyright 2008, Google Inc.
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
** http://www.apache.org/licenses/LICENSE-2.0
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*
**********************************************************************/
#ifndef CACHED_FILE_H
#define CACHED_FILE_H
// The CachedFile class provides a large-cache read access to a file
// It is mainly designed for loading large word dump files
#include <stdio.h>
#include <string>
#ifdef USE_STD_NAMESPACE
using std::string;
#endif
namespace tesseract {
class CachedFile {
public:
explicit CachedFile(string file_name);
~CachedFile();
// reads a specified number of bytes to the specified buffer and
// returns the actual number of bytes read
int Read(void *read_buff, int bytes);
// Returns the file size
long Size();
// returns the current position in the file
long Tell();
// End of file flag
bool eof();
private:
static const unsigned int kCacheSize = 0x8000000;
// file name
string file_name_;
// internal file buffer
unsigned char *buff_;
// file position
long file_pos_;
// file size
long file_size_;
// position of file within buffer
int buff_pos_;
// buffer size
int buff_size_;
// file handle
FILE *fp_;
// Opens the file
bool Open();
};
}
#endif // CACHED_FILE_H