crawl-ref/source/sqldbm.h

   1 /*
   2  *  File:       sqldbm.cc
   3  *  Summary:    dbm wrapper for SQLite
   4  *  Written by: Darshan Shaligram
   5  */
   6
   7 #ifndef SQLDBM_H
   8 #define SQLDBM_H
   9
  10 #ifdef USE_SQLITE_DBM
  11
  12 #include <sys/types.h>
  13 #include <memory>
  14
  15 #define SQLITE_INT64_TYPE int
  16 #define SQLITE_UINT64_TYPE unsigned int
  17
  18 #include <sqlite3.h>
  19 #include <string>
  20
  21 // A string dbm interface for SQLite. Makes no attempt to store arbitrary
  22 // data, only valid C strings.
  23
  24 class sql_datum
  25 {
  26 public:
  27     sql_datum();
  28     sql_datum(const std::string &s);
  29     sql_datum(const sql_datum &other);
  30     virtual ~sql_datum();
  31
  32     sql_datum &operator = (const sql_datum &other);
  33
  34     std::string to_str() const;
  35
  36 public:
  37     char   *dptr;    // Canonically void*, but we're not a real Berkeley DB.
  38     size_t dsize;
  39
  40 private:
  41     bool   need_free;
  42
  43     void reset();
  44     void init_from(const sql_datum &other);
  45 };
  46
  47 #define DBM_REPLACE 1
  48
  49 class SQL_DBM
  50 {
  51 public:
  52     SQL_DBM(const std::string &db = "", bool readonly = true,
  53             bool open = false);
  54     ~SQL_DBM();
  55
  56     bool is_open() const;
  57
  58     int open(const std::string &db = "");
  59     void close();
  60
  61     std::auto_ptr<std::string> firstkey();
  62     std::auto_ptr<std::string> nextkey();
  63
  64     std::string query(const std::string &key);
  65     int insert(const std::string &key, const std::string &value);
  66     int remove(const std::string &key);
  67
  68 public:
  69     std::string error;
  70     int errc;
  71
  72 private:
  73     int finalise_query(sqlite3_stmt **query);
  74     int prepare_query(sqlite3_stmt **query, const char *sql);
  75     int init_query();
  76     int init_iterator();
  77     int init_insert();
  78     int init_remove();
  79     int init_schema();
  80     int ec(int err);
  81
  82     int try_insert(const std::string &key, const std::string &value);
  83     int do_insert(const std::string &key, const std::string &value);
  84     int do_query(const std::string &key, std::string *result);
  85
  86 private:
  87     sqlite3      *db;
  88     sqlite3_stmt *s_insert;
  89     sqlite3_stmt *s_remove;
  90     sqlite3_stmt *s_query;
  91     sqlite3_stmt *s_iterator;
  92     std::string  dbfile;
  93     bool readonly;
  94 };
  95
  96 SQL_DBM  *dbm_open(const char *filename, int open_mode, int permissions);
  97 int   dbm_close(SQL_DBM *db);
  98
  99 sql_datum dbm_fetch(SQL_DBM *db, const sql_datum &key);
 100 sql_datum dbm_firstkey(SQL_DBM *db);
 101 sql_datum dbm_nextkey(SQL_DBM *db);
 102 int dbm_store(SQL_DBM *db, const sql_datum &key,
 103               const sql_datum &value, int overwrite);
 104
 105 typedef sql_datum datum;
 106 typedef SQL_DBM DBM;
 107
 108 #endif
 109
 110 #endif