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//========================================================================
//
// CachedFile.h
//
// Caching files support.
//
// This file is licensed under the GPLv2 or later
//
// Copyright 2009 Stefan Thomas <thomas@eload24.com>
// Copyright 2010 Hib Eris <hib@hiberis.nl>
// Copyright 2010, 2018-2020, 2022 Albert Astals Cid <aacid@kde.org>
//
//========================================================================
#ifndef CACHEDFILE_H
#define CACHEDFILE_H
#include "poppler-config.h"
#include "poppler_private_export.h"
#include "Object.h"
#include "Stream.h"
#include <vector>
//------------------------------------------------------------------------
#define CachedFileChunkSize 8192 // This should be a multiple of cachedStreamBufSize
class GooString;
class CachedFileLoader;
//------------------------------------------------------------------------
// CachedFile
//
// CachedFile gives FILE-like access to a document at a specified URI.
// In the constructor, you specify a CachedFileLoader that handles loading
// the data from the document. The CachedFile requests no more data then it
// needs from the CachedFileLoader.
//------------------------------------------------------------------------
class POPPLER_PRIVATE_EXPORT CachedFile
{
friend class CachedFileWriter;
public:
explicit CachedFile(CachedFileLoader *cacheLoader);
CachedFile(const CachedFile &) = delete;
CachedFile &operator=(const CachedFile &) = delete;
unsigned int getLength() const { return length; }
long int tell();
int seek(long int offset, int origin);
size_t read(void *ptr, size_t unitsize, size_t count);
size_t write(const char *ptr, size_t size, size_t fromByte);
int cache(const std::vector<ByteRange> &ranges);
// Reference counting.
void incRefCnt();
void decRefCnt();
private:
~CachedFile();
enum ChunkState
{
chunkStateNew = 0,
chunkStateLoaded
};
typedef struct
{
ChunkState state;
char data[CachedFileChunkSize];
} Chunk;
int cache(size_t offset, size_t length);
CachedFileLoader *loader;
size_t length;
size_t streamPos;
std::vector<Chunk> *chunks;
int refCnt; // reference count
};
//------------------------------------------------------------------------
// CachedFileWriter
//
// CachedFileWriter handles sequential writes to a CachedFile.
// On construction, you specify the CachedFile and the chunks of it to which data
// should be written.
//------------------------------------------------------------------------
class POPPLER_PRIVATE_EXPORT CachedFileWriter
{
public:
// Construct a CachedFile Writer.
// The caller is responsible for deleting the cachedFile and chunksA.
CachedFileWriter(CachedFile *cachedFile, std::vector<int> *chunksA);
~CachedFileWriter();
// Writes size bytes from ptr to cachedFile, returns number of bytes written.
size_t write(const char *ptr, size_t size);
private:
CachedFile *cachedFile;
std::vector<int> *chunks;
std::vector<int>::iterator it;
size_t offset;
};
//------------------------------------------------------------------------
// CachedFileLoader
//
// CachedFileLoader is an abstact class that specifies the interface for
// loadng data from an URI into a CachedFile.
//------------------------------------------------------------------------
class POPPLER_PRIVATE_EXPORT CachedFileLoader
{
public:
CachedFileLoader() = default;
virtual ~CachedFileLoader();
CachedFileLoader(const CachedFileLoader &) = delete;
CachedFileLoader &operator=(const CachedFileLoader &) = delete;
// Initializes the file load.
// Returns the length of the file.
// The caller is responsible for deleting cachedFile.
virtual size_t init(CachedFile *cachedFile) = 0;
// Loads specified byte ranges and passes it to the writer to store them.
// Returns 0 on success, Anything but 0 on failure.
// The caller is responsible for deleting the writer.
virtual int load(const std::vector<ByteRange> &ranges, CachedFileWriter *writer) = 0;
};
//------------------------------------------------------------------------
#endif