http://www.ousob.com --- Legacy Redefined OuSob - File: /wwwroot/clipx/usr/include/htdig/WordDB.h

// // WordDB.h // // WordDB: Interface to Berkeley DB // uses String and WordReference instead of Dbt, add some convenience // methods and implements string translation of Berkeley DB error codes. // It does not include the 'join' feature. // Beside this, the interface it identical to the Db class. // The next evolution for this set of class is to have a single object per // application so that they all share the same environment (transactions, // shared pool, database directory). This implies a static common object // that is refered by each actual instance of WordDB. The static object // holds the DbEnv and DbInfo, the instances of WordDB only have an open // descriptor using the same DbEnv and DbInfo. // // Part of the ht://Dig package <http://www.htdig.org/> // Copyright (c) 1999-2004 The ht://Dig Group // For copyright details, see the file COPYING in your distribution // or the GNU Library General Public License (LGPL) version 2 or later // <http://www.gnu.org/copyleft/lgpl.html> // // $Id: WordDB.h,v 1.7 2004/05/28 13:15:26 lha Exp $ // #ifndef _WordDB_h_ #define _WordDB_h_ #include <stdio.h> #include <errno.h> #include "db.h" #include "WordReference.h" #include "WordDBInfo.h" #include "htString.h" #define WORD_DBT_DCL(v) \ DBT v; \ memset((char*)&(v), '\0', sizeof(DBT)) #define WORD_DBT_SET(v,d,s) \ v.data = (d); \ v.size = (s) #define WORD_DBT_INIT(v,d,s) \ WORD_DBT_DCL(v); \ WORD_DBT_SET(v,d,s) // // Encapsulate the Berkeley DB DB type // // Implements the same methods with String instead of Dbt. // // Add convenience methods taking WordReference instead of String // // The error model is *not* to use exceptions. // // To get a cursor use the Open method of WordDBCursor. I find this // more convinient than getting a cursor from WordDB. // // The WordDB has DbInfo and DbEnv members that can be set before // calling Open to configure it. // class WordDB { public: inline WordDB() { Alloc(); } inline ~WordDB() { Dealloc(); } inline int Alloc() { db = 0; is_open = 0; dbenv = WordDBInfo::Instance()->dbenv; return CDB_db_create(&db, dbenv, 0); } inline int Dealloc() { int error = 0; is_open = 0; if(db) error = db->close(db, 0); else fprintf(stderr, "WordDB::Dealloc: null db\n"); dbenv = 0; db = 0; return error; } int Open(const String& filename, DBTYPE type, int flags, int mode); inline int Close() { int error; if((error = Dealloc()) != 0) return error; return Alloc(); } inline int Fd(int *fdp) { if(!is_open) return DB_UNKNOWN; return db->fd(db, fdp); } inline int Stat(void *sp, void *(*db_malloc)(size_t), int flags) { if(!is_open) return DB_UNKNOWN; return db->stat(db, sp, db_malloc, (u_int32_t) flags); } inline int Sync(int flags) { if(!is_open) return DB_UNKNOWN; return db->sync(db, (u_int32_t) flags); } inline int get_byteswapped() const { if(!is_open) return DB_UNKNOWN; return db->get_byteswapped(db); } inline DBTYPE get_type() const { if(!is_open) return DB_UNKNOWN; return db->get_type(db); } // // String arguments // inline int Put(DB_TXN *txn, const String& key, const String& data, int flags) { WORD_DBT_INIT(rkey, (void*)key.get(), key.length()); WORD_DBT_INIT(rdata, (void*)data.get(), data.length()); return db->put(db, txn, &rkey, &rdata, flags); } inline int Get(DB_TXN *txn, String& key, String& data, int flags) const { WORD_DBT_INIT(rkey, (void*)key.get(), (u_int32_t)key.length()); WORD_DBT_INIT(rdata, (void*)data.get(), (u_int32_t)data.length()); int error; if((error = db->get(db, txn, &rkey, &rdata, 0)) != 0) { if(error != DB_NOTFOUND) fprintf(stderr, "WordDB::Get(%s,%s) using %d failed %s\n", (char*)key, (char*)data, flags, CDB_db_strerror(error)); } else { // // Only set arguments if found something. // key.set((const char*)rkey.data, (int)rkey.size); data.set((const char*)rdata.data, (int)rdata.size); } return error; } inline int Del(DB_TXN *txn, const String& key) { WORD_DBT_INIT(rkey, (void*)key.get(), (u_int32_t)key.length()); return db->del(db, txn, &rkey, 0); } // // WordReference argument // inline int Put(const WordReference& wordRef, int flags) { if(!is_open) return DB_UNKNOWN; int ret; String key; String record; if((ret = wordRef.Pack(key, record)) != OK) return DB_RUNRECOVERY; return Put(0, key, record, flags); } inline int Del(const WordReference& wordRef) { String key; wordRef.Key().Pack(key); return Del(0, key); } // // Search entry matching wkey exactly, return key and data // in wordRef. // inline int Get(WordReference& wordRef) const { if(!is_open) return DB_UNKNOWN; String data; String key; if(wordRef.Key().Pack(key) != OK) return DB_RUNRECOVERY; int ret; if((ret = Get(0, key, data, 0)) != 0) return ret; return wordRef.Unpack(key, data) == OK ? 0 : DB_RUNRECOVERY; } // // Returns 0 of the key of wordRef matches an entry in the database. // Could be implemented with Get but is not because we don't // need to build a wordRef with the entry found in the base. // inline int Exists(const WordReference& wordRef) const { if(!is_open) return DB_UNKNOWN; String key; String data; if(wordRef.Key().Pack(key) != OK) return DB_RUNRECOVERY; return Get(0, key, data, 0); } // // Accessors // inline int set_bt_compare(int (*compare)(const DBT *, const DBT *)) { return db->set_bt_compare(db, compare); } inline int set_pagesize(u_int32_t pagesize) { return db->set_pagesize(db, pagesize); } // // Accessors for description of the compression scheme // inline DB_CMPR_INFO* CmprInfo() { return dbenv->mp_cmpr_info; } inline void CmprInfo(DB_CMPR_INFO* info) { dbenv->mp_cmpr_info = info; } int is_open; DB* db; DB_ENV* dbenv; }; // // Interface to DBC that uses String instead of DBT // class WordDBCursor { public: inline WordDBCursor() { cursor = 0; } inline ~WordDBCursor() { Close(); } inline int Open(DB* db) { Close(); return db->cursor(db, 0, &cursor, 0); } inline int Close() { if(cursor) cursor->c_close(cursor); cursor = 0; return 0; } // // String arguments // inline int Get(String& key, String& data, int flags) { WORD_DBT_DCL(rkey); WORD_DBT_DCL(rdata); switch(flags & DB_OPFLAGS_MASK) { case DB_SET_RANGE: case DB_SET: case DB_GET_BOTH: WORD_DBT_SET(rkey, (void*)key.get(), key.length()); break; } int error; if((error = cursor->c_get(cursor, &rkey, &rdata, (u_int32_t)flags)) != 0) { if(error != DB_NOTFOUND) fprintf(stderr, "WordDBCursor::Get(%d) failed %s\n", flags, CDB_db_strerror(error)); } else { key.set((const char*)rkey.data, (int)rkey.size); data.set((const char*)rdata.data, (int)rdata.size); } return error; } inline int Put(const String& key, const String& data, int flags) { WORD_DBT_INIT(rkey, (void*)key.get(), (size_t)key.length()); WORD_DBT_INIT(rdata, (void*)data.get(), (size_t)data.length()); return cursor->c_put(cursor, &rkey, &rdata, (u_int32_t)flags); } inline int Del() { return cursor->c_del(cursor, (u_int32_t)0); } private: DBC* cursor; }; #endif /* _WordDB_h */