Annotation of parser3/src/include/pa_db_table.h, revision 1.2
1.1 paf 1: /** @file
2: Parser: sql db decl.
3:
4: Copyright (c) 2001 ArtLebedev Group (http://www.artlebedev.com)
5: Author: Alexander Petrosyan <paf@design.ru> (http://design.ru/paf)
6:
1.2 ! paf 7: $Id: pa_db_table.h,v 1.1 2001/10/25 13:18:19 paf Exp $
1.1 paf 8: */
9:
10: #ifndef PA_DB_TABLE_H
11: #define PA_DB_TABLE_H
12:
13: #include "pa_config_includes.h"
14: #include "pa_pool.h"
15: #include "pa_db_connection.h"
16: #include "pa_globals.h"
17:
18: #ifdef HAVE_DB_H
19: # include <db.h>
20: #endif
21:
22: // defines
23:
24: #define PA_DB_ACCESS_METHOD DB_BTREE
25:
26: // forwards
27:
1.2 ! paf 28: class DB_Transaction;
1.1 paf 29: class DB_Cursor;
30:
31: // class
32:
33: /// DB table. handy wrapper around low level <db.h> calls
34: class DB_Table : public Pooled {
1.2 ! paf 35: friend DB_Transaction;
1.1 paf 36: friend DB_Cursor;
37: public:
38:
39: DB_Table(Pool& pool, const String& afile_spec, DB_Connection& aconnection);
40:
41: void set_services(Pool *aservices_pool) {
42: time_used=time(0); // they started to use at this time
43: fservices_pool=aservices_pool;
44: }
45: bool expired(time_t older_dies) {
46: return time_used<older_dies;
47: }
48:
49: void close() {
50: fconnection.close_table(ffile_spec, *this);
51: }
52:
53: bool connected() { return db!=0; }
54: void connect();
55: void disconnect();
56: bool ping() { return errors==0; }
57:
58: void put(const String& key, const String& data, time_t time_to_die);
59: String *get(const String& key);
60: void remove(const String& key);
61:
62: private:
63:
64: DB_Connection& fconnection;
65: DB_ENV& dbenv;
66: const String& ffile_spec; const char *file_spec_cstr;
67: Pool *fservices_pool;
68: DB *db;
69: int errors;
1.2 ! paf 70: DB_TXN *ftid; bool ftid_has_parent;
1.1 paf 71: time_t time_used;
72:
73: private: // transaction
74:
75: /// commits current transaction, restores previous transaction handle
1.2 ! paf 76: void commit_restore(DB_TXN *atid, bool atid_has_parent) {
! 77: if(ftid && !atid_has_parent) // it's parent responsibility to do that
1.1 paf 78: check("txn_commit", &ffile_spec, txn_commit(ftid));
79:
80: ftid=atid;
1.2 ! paf 81: ftid_has_parent=atid_has_parent;
1.1 paf 82: }
83:
84: /// rolls current transaction back, restores previous transaction handle
1.2 ! paf 85: void rollback_restore(DB_TXN *atid, bool atid_has_parent) {
! 86: if(ftid && !atid_has_parent) // it's parent responsibility to do that
1.1 paf 87: check("txn_abort", &ffile_spec, txn_abort(ftid));
88:
89: ftid=atid;
1.2 ! paf 90: ftid_has_parent=atid_has_parent;
1.1 paf 91: }
92:
93: /// stars new current trunsaction @returns previous transaction handle
1.2 ! paf 94: void transaction_begin_save(DB_TXN *& rtid, bool& rtid_has_parent) {
! 95: rtid=ftid;
! 96: rtid_has_parent=ftid_has_parent;
! 97: check("txn_begin", &ffile_spec, ::txn_begin(dbenv.tx_info, rtid, &ftid));
! 98: ftid_has_parent=rtid!=0;
1.1 paf 99: }
100:
101: private:
102:
103: void check(const char *operation, const String *source, int error);
104: void *malloc(size_t size) { return fservices_pool->malloc(size); }
105: void *calloc(size_t size) { return fservices_pool->calloc(size); }
106: /// pass empty dbt, would fill it from string
107: void key_string_to_dbt(const String& key_string, DBT& key_result);
108: /// @returns new string
109: String& key_dbt_to_string(const DBT& key_dbt);
110: /// pass empty dbt, would fill it from string
111: void data_string_to_dbt(const String& data_string, time_t time_to_die,
112: DBT& data_result);
113: /// @returns new string if it not expired
114: String *data_dbt_to_string(const DBT& data_dbt);
115:
116: };
117:
118: /// Auto-object used for temporary changing DB_Table::tid.
1.2 ! paf 119: class DB_Transaction {
1.1 paf 120: DB_Table& ftable;
121: bool marked_to_rollback;
1.2 ! paf 122: DB_TXN *saved_tid; bool saved_tid_has_parent;
1.1 paf 123: public:
1.2 ! paf 124: DB_Transaction(DB_Table& atable) : ftable(atable), marked_to_rollback(false) {
! 125: atable.transaction_begin_save(saved_tid, saved_tid_has_parent);
1.1 paf 126: }
1.2 ! paf 127: ~DB_Transaction() {
1.1 paf 128: if(marked_to_rollback)
1.2 ! paf 129: ftable.rollback_restore(saved_tid, saved_tid_has_parent);
1.1 paf 130: else
1.2 ! paf 131: ftable.commit_restore(saved_tid, saved_tid_has_parent);
1.1 paf 132: }
133: void mark_to_rollback() {
134: marked_to_rollback=true;
135: }
136: };
137:
138: /// DB cursor. handy wrapper around low level <db.h> calls
139: class DB_Cursor {
140: friend DB_Table;
141: public:
142: DB_Cursor(DB_Table& atable, const String *asource);
143: ~DB_Cursor();
144: /// pass empty strings to key&data, would fill them
145: bool get(String *& key, String *& data, u_int32_t flags);
146: void remove(u_int32_t flags);
147: private:
148: const String *fsource;
149: DB_Table& ftable;
150: DBC *cursor;
151: private:
152: void check(const char *operation, const String *source, int error) {
153: ftable.check(operation, source, error);
154: }
155: /// @returns new string
156: String& key_dbt_to_string(DBT& key_dbt) {
157: return ftable.key_dbt_to_string(key_dbt);
158: }
159: /// @returns new string if it not expired
160: String *data_dbt_to_string(const DBT& data_dbt) {
161: return ftable.data_dbt_to_string(data_dbt);
162: }
163: };
164:
165: #endif
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