* Finished (mostly) the Sleepycat DB backend ... added transaction logging

[citadel.git] / citadel / database_sleepycat.c

diff --git a/citadel/database_sleepycat.c b/citadel/database_sleepycat.c
index f8bb3dc0580357a5679dcfe876dbdfe2e3b2098e..9731c9a7aba035c378913d6f5ab3694c639b569b 100644 (file)
--- a/citadel/database_sleepycat.c
+++ b/citadel/database_sleepycat.c
@@ -19,18 +19,51 @@
 #include "citserver.h"
 #include "database.h"
 #include "sysdep_decls.h"
+#include "dynloader.h"
 
 
+/* 
+ * FIXME this should be defined somewhere else.
+ */
+int transaction_based = 1;
+
+DB *dbp[MAXCDB];               /* One DB handle for each Citadel database */
+DB_ENV *dbenv;                 /* The DB environment (global) */
+
+struct cdbssd {                        /* Session-specific DB stuff */
+       DBC *cursor;            /* Cursor, for traversals... */
+       DB_TXN *tid;            /* Transaction ID */
+};
+
+struct cdbssd *ssd_arr = NULL;
+int num_ssd = 0;
+#define MYCURSOR       ssd_arr[CC->cs_pid].cursor
+#define MYTID          ssd_arr[CC->cs_pid].tid
+
 /*
- * This array holds one DB handle for each Citadel database.
+ * Ensure that we have enough space for session-specific data.  We don't
+ * put anything in here that Citadel cares about; this is just database
+ * related stuff like cursors and transactions.
  */
-DB *dbp[MAXCDB];
+void cdb_allocate_ssd(void) {
+       /*
+        * Make sure we have a cursor allocated for this session
+        */
 
-DB_ENV *dbenv;
+       lprintf(9, "num_ssd before realloc = %d\n", num_ssd);
+       if (num_ssd <= CC->cs_pid) {
+               num_ssd = CC->cs_pid + 1;
+               if (ssd_arr == NULL) {
+                       ssd_arr = (struct cdbssd *)
+                           mallok((sizeof(struct cdbssd) * num_ssd));
+               } else {
+                       ssd_arr = (struct cdbssd *)
+                           reallok(ssd_arr, (sizeof(struct cdbssd) * num_ssd));
+               }
+       }
+       lprintf(9, "num_ssd  after realloc = %d\n", num_ssd);
+}
 
-DBC **cursorz = NULL;
-int num_cursorz = 0;
-#define MYCURSOR cursorz[CC->cs_pid]
 
 /*
  * Reclaim unused space in the databases.  We need to do each one of
@@ -56,6 +89,7 @@ void open_databases(void)
        int ret;
        int i;
        char dbfilename[256];
+       u_int32_t flags = 0;
 
         /*
          * Silently try to create the database subdirectory.  If it's
@@ -89,10 +123,9 @@ void open_databases(void)
         * is serialized already, so don't bother the database manager with
         * it.  Besides, it locks up when we do it that way.
          */
-        /* (void)dbenv->set_data_dir(dbenv, "/database/files"); */
-        ret = dbenv->open(dbenv, "./data",
-               ( DB_CREATE | DB_INIT_MPOOL | DB_PRIVATE ),
-               0);
+        flags = DB_CREATE | DB_INIT_MPOOL | DB_PRIVATE;
+       if (transaction_based) flags = flags | DB_INIT_TXN;
+        ret = dbenv->open(dbenv, "./data", flags, 0);
        if (ret) {
                lprintf(1, "dbenv->open: %s\n", db_strerror(ret));
                 dbenv->close(dbenv, 0);
@@ -129,6 +162,10 @@ void open_databases(void)
 
        }
 
+       cdb_allocate_ssd();
+       CtdlRegisterSessionHook(cdb_allocate_ssd, EVT_START);
+
+
 }
 
 
@@ -186,7 +223,7 @@ int cdb_store(int cdb,
 
        begin_critical_section(S_DATABASE);
        ret = dbp[cdb]->put(dbp[cdb],           /* db */
-                               NULL,           /* transaction ID (hmm...) */
+                               MYTID,          /* transaction ID */
                                &dkey,          /* key */
                                &ddata,         /* data */
                                0);             /* flags */
@@ -212,7 +249,7 @@ int cdb_delete(int cdb, void *key, int keylen)
        dkey.data = key;
 
        begin_critical_section(S_DATABASE);
-       ret = dbp[cdb]->del(dbp[cdb], NULL, &dkey, 0);
+       ret = dbp[cdb]->del(dbp[cdb], MYTID, &dkey, 0);
        end_critical_section(S_DATABASE);
        return (ret);
 
@@ -240,7 +277,7 @@ struct cdbdata *cdb_fetch(int cdb, void *key, int keylen)
        dret.flags = DB_DBT_MALLOC;
 
        begin_critical_section(S_DATABASE);
-       ret = dbp[cdb]->get(dbp[cdb], NULL, &dkey, &dret, 0);
+       ret = dbp[cdb]->get(dbp[cdb], MYTID, &dkey, &dret, 0);
        end_critical_section(S_DATABASE);
        if ((ret != 0) && (ret != DB_NOTFOUND)) {
                lprintf(1, "cdb_fetch: %s\n", db_strerror(ret));
@@ -276,27 +313,13 @@ void cdb_rewind(int cdb)
 {
        int ret = 0;
 
-       /*
-        * Make sure we have a cursor allocated for this session
-        */
-
-       if (num_cursorz <= CC->cs_pid) {
-               num_cursorz = CC->cs_pid + 1;
-               if (cursorz == NULL) {
-                       cursorz = (DBC **)
-                           mallok((sizeof(DBC *) * num_cursorz));
-               } else {
-                       cursorz = (DBC **)
-                           reallok(cursorz, (sizeof(DBC *) * num_cursorz));
-               }
-       }
-
+       cdb_allocate_ssd();
 
        /*
         * Now initialize the cursor
         */
        begin_critical_section(S_DATABASE);
-       ret = dbp[cdb]->cursor(dbp[cdb], NULL, &MYCURSOR, 0);
+       ret = dbp[cdb]->cursor(dbp[cdb], MYTID, &MYCURSOR, 0);
        if (ret) {
                lprintf(1, "db_cursor: %s\n", db_strerror(ret));
        }
@@ -332,3 +355,21 @@ struct cdbdata *cdb_next_item(int cdb)
 
        return (cdbret);
 }
+
+
+/*
+ * Transaction-based stuff.  I'm writing this as I bake cookies...
+ */
+
+void cdb_begin_transaction(void) {
+       if (!transaction_based) {
+               MYTID = NULL;
+               return;
+       }
+
+       txn_begin(dbenv, NULL, &MYTID, 0);
+}
+
+void cdb_end_transaction(void) {
+       if (transaction_based) txn_commit(MYTID, 0);
+}