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/* -*- Mode: C; tab-width: 4; c-basic-offset: 4; indent-tabs-mode: nil -*- */
#include "config.h"
#include <ctype.h>
#include <stdio.h>
#include <string.h>
#include <dlfcn.h>
#include "utilities/engine_loader.h"
#include <memcached/types.h>
static const char * const feature_descriptions[] = {
"compare and swap",
"persistent storage",
"secondary engine",
"access control",
"multi tenancy",
"LRU"
};
void *handle = NULL;
bool load_engine(const char *soname,
SERVER_HANDLE_V1 *(*get_server_api)(void),
EXTENSION_LOGGER_DESCRIPTOR *logger,
ENGINE_HANDLE **engine_handle)
{
ENGINE_HANDLE *engine = NULL;
/* Hack to remove the warning from C99 */
union my_hack {
CREATE_INSTANCE create;
void* voidptr;
} my_create = {.create = NULL };
handle = dlopen(soname, RTLD_NOW | RTLD_LOCAL);
if (handle == NULL) {
const char *msg = dlerror();
logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to open library \"%s\": %s\n",
soname ? soname : "self",
msg ? msg : "unknown error");
return false;
}
void *symbol = dlsym(handle, "create_instance");
if (symbol == NULL) {
logger->log(EXTENSION_LOG_WARNING, NULL,
"Could not find symbol \"create_instance\" in %s: %s\n",
soname ? soname : "self",
dlerror());
return false;
}
my_create.voidptr = symbol;
/* request a instance with protocol version 1 */
ENGINE_ERROR_CODE error = (*my_create.create)(1, get_server_api, &engine);
if (error != ENGINE_SUCCESS || engine == NULL) {
logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to create instance. Error code: %d\n", error);
dlclose(handle);
return false;
}
*engine_handle = engine;
return true;
}
bool init_engine(ENGINE_HANDLE * engine,
const char *config_str,
EXTENSION_LOGGER_DESCRIPTOR *logger)
{
ENGINE_HANDLE_V1 *engine_v1 = NULL;
if (handle == NULL) {
logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to initialize engine, engine must fist be loaded.");
return false;
}
if (engine->interface == 1) {
engine_v1 = (ENGINE_HANDLE_V1*)engine;
// validate that the required engine interface is implemented:
if (engine_v1->get_info == NULL || engine_v1->initialize == NULL ||
engine_v1->destroy == NULL || engine_v1->allocate == NULL ||
engine_v1->remove == NULL || engine_v1->release == NULL ||
engine_v1->get == NULL || engine_v1->store == NULL ||
engine_v1->flush == NULL ||
engine_v1->get_stats == NULL || engine_v1->reset_stats == NULL ||
engine_v1->item_set_cas == NULL ||
engine_v1->get_item_info == NULL)
{
logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to initialize engine; it does not implement the engine interface.");
return false;
}
ENGINE_ERROR_CODE error = engine_v1->initialize(engine,config_str);
if (error != ENGINE_SUCCESS) {
engine_v1->destroy(engine, false);
logger->log(EXTENSION_LOG_WARNING, NULL,
"Failed to initialize instance. Error code: %d\n",
error);
dlclose(handle);
return false;
}
} else {
logger->log(EXTENSION_LOG_WARNING, NULL,
"Unsupported interface level\n");
dlclose(handle);
return false;
}
return true;
}
void log_engine_details(ENGINE_HANDLE * engine,
EXTENSION_LOGGER_DESCRIPTOR *logger)
{
ENGINE_HANDLE_V1 *engine_v1 = (ENGINE_HANDLE_V1*)engine;
const engine_info *info;
info = engine_v1->get_info(engine);
if (info) {
char message[4096];
ssize_t nw = snprintf(message, sizeof(message), "Loaded engine: %s\n",
info->description ?
info->description : "Unknown");
if (nw == -1) {
return;
}
ssize_t offset = nw;
bool comma = false;
if (info->num_features > 0) {
nw = snprintf(message + offset, sizeof(message) - offset,
"Supplying the following features: ");
if (nw == -1) {
return;
}
offset += nw;
for (int ii = 0; ii < info->num_features; ++ii) {
if (info->features[ii].description != NULL) {
// We don't want to write partially from source
if (sizeof(message)-offset <=
2+strlen(info->features[ii].description))
{
return;
}
nw = snprintf(message + offset, sizeof(message) - offset,
"%s%s", comma ? ", " : "",
info->features[ii].description);
} else {
if (info->features[ii].feature <= LAST_REGISTERED_ENGINE_FEATURE) {
nw = snprintf(message + offset, sizeof(message) - offset,
"%s%s", comma ? ", " : "",
feature_descriptions[info->features[ii].feature]);
} else {
nw = snprintf(message + offset, sizeof(message) - offset,
"%sUnknown feature: %d", comma ? ", " : "",
info->features[ii].feature);
}
}
comma = true;
if (nw == -1) {
return;
}
offset += nw;
}
}
logger->log(EXTENSION_LOG_INFO, NULL, "%s\n", message);
} else {
logger->log(EXTENSION_LOG_INFO, NULL,
"Loaded engine: Unknown\n");
}
}
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