//========================================================================

//

// XRef.h

//

// Copyright 1996-2003 Glyph & Cog, LLC

//

//========================================================================

#ifndef XREF_H

#define XREF_H

#include <aconf.h>

#ifdef USE_GCC_PRAGMAS

#pragma interface

#endif

#include "gtypes.h"

#include "gfile.h"

#include "Object.h"

#if MULTITHREADED

#include "GMutex.h"

#endif

class Dict;

class Stream;

class Parser;

class ObjectStream;

class XRefPosSet;

//------------------------------------------------------------------------

// XRef

//------------------------------------------------------------------------

enum XRefEntryType {

  xrefEntryFree,

  xrefEntryUncompressed,

  xrefEntryCompressed

};

struct XRefEntry {

  GFileOffset offset;

  int gen;

  XRefEntryType type;

};

struct XRefCacheEntry {

  int num;

  int gen;

  Object obj;

};

#define xrefCacheSize 16

#define objStrCacheSize 128

#define objStrCacheTimeout 1000

class XRef {

public:

  // Constructor.  Read xref table from stream.

  XRef(BaseStream *strA, GBool repair);

  // Destructor.

  ~XRef();

  // Is xref table valid?

  GBool isOk() { return ok; }

  // Get the error code (if isOk() returns false).

  int getErrorCode() { return errCode; }

  // Set the encryption parameters.

  void setEncryption(int permFlagsA, GBool ownerPasswordOkA,

         Guchar *fileKeyA, int keyLengthA, int encVersionA,

         CryptAlgorithm encAlgorithmA);

  // Is the file encrypted?

  GBool isEncrypted() { return encrypted; }

  GBool getEncryption(int *permFlagsA, GBool *ownerPasswordOkA,

          int *keyLengthA, int *encVersionA,

          CryptAlgorithm *encAlgorithmA);

  // Check various permissions.

  GBool okToPrint(GBool ignoreOwnerPW = gFalse);

  GBool okToChange(GBool ignoreOwnerPW = gFalse);

  GBool okToCopy(GBool ignoreOwnerPW = gFalse);

  GBool okToAddNotes(GBool ignoreOwnerPW = gFalse);

  int getPermFlags() { return permFlags; }

  // Get catalog object.

  Object *getCatalog(Object *obj) { return fetch(rootNum, rootGen, obj); }

  // Fetch an indirect reference.

  Object *fetch(int num, int gen, Object *obj, int recursion = 0);

  // Return the document's Info dictionary (if any).

  Object *getDocInfo(Object *obj);

  Object *getDocInfoNF(Object *obj);

  // Return the number of objects in the xref table.

  int getNumObjects() { return last + 1; }

  // Return the offset of the last xref table.

  GFileOffset getLastXRefPos() { return lastXRefPos; }

  // Return the offset of the 'startxref' at the end of the file.

  GFileOffset getLastStartxrefPos() { return lastStartxrefPos; }

  // Return the catalog object reference.

  int getRootNum() { return rootNum; }

  int getRootGen() { return rootGen; }

  // Get the xref table positions.

  int getNumXRefTables() { return xrefTablePosLen; }

  GFileOffset getXRefTablePos(int idx) { return xrefTablePos[idx]; }

  // Get end position for a stream in a damaged file.

  // Returns false if unknown or file is not damaged.

  GBool getStreamEnd(GFileOffset streamStart, GFileOffset *streamEnd);

  // Direct access.

  int getSize() { return size; }

  XRefEntry *getEntry(int i) { return &entries[i]; }

  Object *getTrailerDict() { return &trailerDict; }

private:

  BaseStream *str;    // input stream

  GFileOffset start;    // offset in file (to allow for garbage

        //   at beginning of file)

  XRefEntry *entries;   // xref entries

  int size;     // size of <entries> array

  int last;     // last used index in <entries>

  int rootNum, rootGen;   // catalog dict

  GBool ok;     // true if xref table is valid

  int errCode;      // error code (if <ok> is false)

  Object trailerDict;   // trailer dictionary

  GFileOffset lastXRefPos;  // offset of last xref table

  GFileOffset lastStartxrefPos; // offset of 'startxref' at end of file

  GFileOffset *xrefTablePos;  // positions of all xref tables

  int xrefTablePosLen;    // number of xref table positions

  GFileOffset *streamEnds;  // 'endstream' positions - only used in

        //   damaged files

  int streamEndsLen;    // number of valid entries in streamEnds

  ObjectStream *    // cached object streams

    objStrs[objStrCacheSize];

  int objStrCacheLength;  // number of valid entries in objStrs[]

  Guint       // time of last use for each obj stream

    objStrLastUse[objStrCacheSize];

  Guint objStrTime;   // current time for the obj stream cache

#if MULTITHREADED

  GMutex objStrsMutex;

#endif

  GBool encrypted;    // true if file is encrypted

  int permFlags;    // permission bits

  GBool ownerPasswordOk;  // true if owner password is correct

  Guchar fileKey[32];   // file decryption key

  int keyLength;    // length of key, in bytes

  int encVersion;   // encryption version

  CryptAlgorithm encAlgorithm;  // encryption algorithm

  XRefCacheEntry    // cache of recently accessed objects

    cache[xrefCacheSize];

#if MULTITHREADED

  GMutex cacheMutex;

#endif

  GFileOffset getStartXref();

  GBool readXRef(GFileOffset *pos, XRefPosSet *posSet, GBool hybrid);

  GBool readXRefTable(GFileOffset *pos, int offset, XRefPosSet *posSet);

  GBool readXRefStream(Stream *xrefStr, GFileOffset *pos, GBool hybrid);

  GBool readXRefStreamSection(Stream *xrefStr, int *w, int first, int n);

  GBool constructXRef();

  void constructTrailerDict(GFileOffset pos);

  void saveTrailerDict(Dict *dict, GBool isXRefStream);

  char *constructObjectEntry(char *p, GFileOffset pos, int *objNum);

  void constructObjectStreamEntries(Object *objStr, int objStrObjNum);

  GBool constructXRefEntry(int num, int gen, GFileOffset pos,

         XRefEntryType type);

  GBool getObjectStreamObject(int objStrNum, int objIdx,

            int objNum, Object *obj);

  ObjectStream *getObjectStream(int objStrNum);

  void cleanObjectStreamCache();

  GFileOffset strToFileOffset(char *s);

};

#endif