ftparchive/cachedb.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 // $Id: cachedb.h,v 1.4 2004/05/08 19:41:01 mdz Exp $
   4 /* ######################################################################
   5
   6    CacheDB
   7
   8    Simple uniform interface to a cache database.
   9
  10    ##################################################################### */
  11                                                                         /*}}}*/
  12 #ifndef CACHEDB_H
  13 #define CACHEDB_H
  14
  15 #ifdef __GNUG__
  16 #pragma interface "cachedb.h"
  17 #endif
  18
  19 #include <db.h>
  20 #include <string>
  21 #include <apt-pkg/debfile.h>
  22 #include <inttypes.h>
  23 #include <sys/stat.h>
  24 #include <errno.h>
  25
  26 #include "contents.h"
  27
  28 class CacheDB
  29 {
  30    protected:
  31
  32    // Database state/access
  33    DBT Key;
  34    DBT Data;
  35    char TmpKey[600];
  36    DB *Dbp;
  37    bool DBLoaded;
  38    bool ReadOnly;
  39    string DBFile;
  40
  41    // Generate a key for the DB of a given type
  42    inline void InitQuery(const char *Type)
  43    {
  44       memset(&Key,0,sizeof(Key));
  45       memset(&Data,0,sizeof(Data));
  46       Key.data = TmpKey;
  47       Key.size = snprintf(TmpKey,sizeof(TmpKey),"%s:%s",Type,FileName.c_str());
  48    }
  49
  50    inline bool Get()
  51    {
  52       return Dbp->get(Dbp,0,&Key,&Data,0) == 0;
  53    };
  54    inline bool Put(const void *In,unsigned long Length)
  55    {
  56       if (ReadOnly == true)
  57          return true;
  58       Data.size = Length;
  59       Data.data = (void *)In;
  60       if (DBLoaded == true && (errno = Dbp->put(Dbp,0,&Key,&Data,0)) != 0)
  61       {
  62          DBLoaded = false;
  63          return false;
  64       }
  65       return true;
  66    }
  67
  68    // Stat info stored in the DB, Fixed types since it is written to disk.
  69    enum FlagList {FlControl = (1<<0),FlMD5=(1<<1),FlContents=(1<<2)};
  70    struct StatStore
  71    {
  72       uint32_t mtime;
  73       uint32_t Flags;
  74    } CurStat;
  75    struct StatStore OldStat;
  76
  77    // 'set' state
  78    string FileName;
  79    struct stat FileStat;
  80    FileFd *Fd;
  81    debDebFile *DebFile;
  82
  83    public:
  84
  85    // Data collection helpers
  86    debDebFile::MemControlExtract Control;
  87    ContentsExtract Contents;
  88
  89    // Runtime statistics
  90    struct Stats
  91    {
  92       double Bytes;
  93       double MD5Bytes;
  94       unsigned long Packages;
  95       unsigned long Misses;
  96       unsigned long DeLinkBytes;
  97
  98       inline void Add(const Stats &S) {Bytes += S.Bytes; MD5Bytes += S.MD5Bytes;
  99          Packages += S.Packages; Misses += S.Misses; DeLinkBytes += S.DeLinkBytes;};
 100       Stats() : Bytes(0), MD5Bytes(0), Packages(0), Misses(0), DeLinkBytes(0) {};
 101    } Stats;
 102
 103    bool ReadyDB(string DB);
 104    inline bool DBFailed() {return Dbp != 0 && DBLoaded == false;};
 105    inline bool Loaded() {return DBLoaded == true;};
 106
 107    bool SetFile(string FileName,struct stat St,FileFd *Fd);
 108    bool LoadControl();
 109    bool LoadContents(bool GenOnly);
 110    bool GetMD5(string &MD5Res,bool GenOnly);
 111    bool Finish();
 112
 113    bool Clean();
 114
 115    CacheDB(string DB) : Dbp(0), DebFile(0) {ReadyDB(DB);};
 116    ~CacheDB() {ReadyDB(string()); delete DebFile;};
 117 };
 118
 119 #endif