remerging wsrep files from lp:codership-mysql

1 files changed, 199 insertions, 0 deletions

diff --git a/wsrep/wsrep_loader.c b/wsrep/wsrep_loader.c
new file mode 100644
index 00000000000..b4460658f80
--- /dev/null
+++ b/wsrep/wsrep_loader.c
@@ -0,0 +1,199 @@
+/* Copyright (C) 2009-2011 Codership Oy <info@codersihp.com>
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; version 2 of the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+/*! @file wsrep implementation loader */
+
+#include <dlfcn.h>
+#include <errno.h>
+#include <string.h>
+#include <stdio.h>
+
+#include "wsrep_api.h"
+
+// Logging stuff for the loader
+static const char* log_levels[] = {"FATAL", "ERROR", "WARN", "INFO", "DEBUG"};
+
+static void default_logger (wsrep_log_level_t lvl, const char* msg)
+{
+    fprintf (stderr, "wsrep loader: [%s] %s\n", log_levels[lvl], msg);
+}
+
+static wsrep_log_cb_t logger = default_logger;
+
+/**************************************************************************
+ * Library loader
+ **************************************************************************/
+
+static int verify(const wsrep_t *wh, const char *iface_ver)
+{
+    const size_t msg_len = 128;
+    char msg[msg_len];
+
+#define VERIFY(_p) if (!(_p)) {                                       \
+        snprintf(msg, msg_len, "wsrep_load(): verify(): %s\n", # _p); \
+        logger (WSREP_LOG_ERROR, msg);                                \
+        return EINVAL;                                                \
+    }
+
+    VERIFY(wh);
+    VERIFY(wh->version);
+
+    if (strcmp(wh->version, iface_ver)) {
+        snprintf (msg, msg_len,
+                  "provider interface version mismatch: need '%s', found '%s'",
+                  iface_ver, wh->version);
+        logger (WSREP_LOG_ERROR, msg);
+        return EINVAL;
+    }
+
+    VERIFY(wh->init);
+    VERIFY(wh->options_set);
+    VERIFY(wh->options_get);
+    VERIFY(wh->connect);
+    VERIFY(wh->disconnect);
+    VERIFY(wh->recv);
+    VERIFY(wh->pre_commit);
+    VERIFY(wh->post_commit);
+    VERIFY(wh->post_rollback);
+    VERIFY(wh->replay_trx);
+    VERIFY(wh->abort_pre_commit);
+    VERIFY(wh->append_query);
+    VERIFY(wh->append_key);
+    VERIFY(wh->free_connection);
+    VERIFY(wh->to_execute_start);
+    VERIFY(wh->to_execute_end);
+    VERIFY(wh->sst_sent);
+    VERIFY(wh->sst_received);
+    VERIFY(wh->stats_get);
+    VERIFY(wh->stats_free);
+    VERIFY(wh->pause);
+    VERIFY(wh->resume);
+    VERIFY(wh->desync);
+    VERIFY(wh->resync);
+    VERIFY(wh->lock);
+    VERIFY(wh->unlock);
+    VERIFY(wh->is_locked);
+    VERIFY(wh->provider_name);
+    VERIFY(wh->provider_version);
+    VERIFY(wh->provider_vendor);
+    VERIFY(wh->free);
+    return 0;
+}
+
+
+static wsrep_loader_fun wsrep_dlf(void *dlh, const char *sym)
+{
+    union {
+        wsrep_loader_fun dlfun;
+        void *obj;
+    } alias;
+    alias.obj = dlsym(dlh, sym);
+    return alias.dlfun;
+}
+
+extern int wsrep_dummy_loader(wsrep_t *w);
+
+int wsrep_load(const char *spec, wsrep_t **hptr, wsrep_log_cb_t log_cb)
+{
+    int ret = 0;
+    void *dlh = NULL;
+    wsrep_loader_fun dlfun;
+    const size_t msg_len = 1024;
+    char msg[msg_len + 1];
+    msg[msg_len] = 0;
+
+    if (NULL != log_cb)
+        logger = log_cb;
+
+    if (!(spec && hptr))
+        return EINVAL;
+
+    snprintf (msg, msg_len,
+              "wsrep_load(): loading provider library '%s'", spec);
+    logger (WSREP_LOG_INFO, msg);
+
+    if (!(*hptr = malloc(sizeof(wsrep_t)))) {
+        logger (WSREP_LOG_FATAL, "wsrep_load(): out of memory");
+        return ENOMEM;
+    }
+
+    if (!spec || strcmp(spec, WSREP_NONE) == 0) {
+        if ((ret = wsrep_dummy_loader(*hptr)) != 0) {
+            free (*hptr);
+            *hptr = NULL;
+        }
+        return ret;
+    }
+
+    if (!(dlh = dlopen(spec, RTLD_NOW | RTLD_LOCAL))) {
+        snprintf(msg, msg_len, "wsrep_load(): dlopen(): %s", dlerror());
+        logger (WSREP_LOG_ERROR, msg);
+        ret = EINVAL;
+        goto out;
+    }
+
+    if (!(dlfun = wsrep_dlf(dlh, "wsrep_loader"))) {
+        ret = EINVAL;
+        goto out;
+    }
+
+    if ((ret = (*dlfun)(*hptr)) != 0) {
+        snprintf(msg, msg_len, "wsrep_load(): loader failed: %s",
+                 strerror(ret));
+        logger (WSREP_LOG_ERROR, msg);
+        goto out;
+    }
+
+    if ((ret = verify(*hptr, WSREP_INTERFACE_VERSION)) != 0) {
+        snprintf (msg, msg_len,
+                  "wsrep_load(): interface version mismatch: my version %s, "
+                  "provider version %s", WSREP_INTERFACE_VERSION,
+                  (*hptr)->version);
+        logger (WSREP_LOG_ERROR, msg);
+        goto out;
+    }
+
+    (*hptr)->dlh = dlh;
+
+out:
+    if (ret != 0) {
+        if (dlh) dlclose(dlh);
+        free(*hptr);
+        *hptr = NULL;
+    } else {
+        snprintf (msg, msg_len,
+                  "wsrep_load(): %s %s by %s loaded succesfully.",
+                  (*hptr)->provider_name, (*hptr)->provider_version,
+                  (*hptr)->provider_vendor);
+        logger (WSREP_LOG_INFO, msg);
+    }
+
+    return ret;
+}
+
+void wsrep_unload(wsrep_t *hptr)
+{
+    if (!hptr) {
+        logger (WSREP_LOG_WARN, "wsrep_unload(): null pointer.");
+    } else {
+        if (hptr->free)
+            hptr->free(hptr);
+        if (hptr->dlh)
+            dlclose(hptr->dlh);
+        free(hptr);
+    }
+}
+