/*
* __conn_config_env --
* Read configuration from an environment variable, if set.
*/
static int
__conn_config_env(WT_SESSION_IMPL *session, const char **cfg)
{
WT_CONFIG_ITEM cval;
const char *env_config;
if ((env_config = getenv("WIREDTIGER_CONFIG")) == NULL ||
strlen(env_config) == 0)
return (0);
/*
* Security stuff:
*
* If the "use_environment_priv" configuration string is set, use the
* environment variable if the process has appropriate privileges.
*/
WT_RET(__wt_config_gets(session, cfg, "use_environment_priv", &cval));
if (cval.val == 0 && __wt_has_priv())
WT_RET_MSG(session, WT_ERROR, "%s",
"WIREDTIGER_CONFIG environment variable set but process "
"lacks privileges to use that environment variable");
/* Check the configuration string. */
WT_RET(__wt_config_check(
session, __wt_confchk_wiredtiger_open, env_config, 0));
/*
* The environment setting comes second-to-last: it overrides the
* WiredTiger.config file (if any), but not the config passed by the
* application.
*/
while (cfg[1] != NULL)
++cfg;
cfg[1] = cfg[0];
cfg[0] = env_config;
return (0);
}
/*
* wiredtiger_open --
* Main library entry point: open a new connection to a WiredTiger
* database.
*/
int
wiredtiger_open(const char *home, WT_EVENT_HANDLER *event_handler,
const char *config, WT_CONNECTION **wt_connp)
{
static WT_CONNECTION stdc = {
__conn_close,
__conn_reconfigure,
__conn_get_home,
__conn_is_new,
__conn_open_session,
__conn_load_extension,
__conn_add_data_source,
__conn_add_collator,
__conn_add_compressor,
__conn_add_extractor
};
static struct {
const char *name;
uint32_t flag;
} *ft, directio_types[] = {
{ "data", WT_DIRECTIO_DATA },
{ "log", WT_DIRECTIO_LOG },
{ NULL, 0 }
};
WT_CONFIG subconfig;
WT_CONFIG_ITEM cval, skey, sval;
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
WT_ITEM *cbuf, expath, exconfig;
WT_SESSION_IMPL *session;
const char *cfg[] =
{ __wt_confdfl_wiredtiger_open, config, NULL, NULL, NULL };
int exist;
*wt_connp = NULL;
session = NULL;
cbuf = NULL;
WT_CLEAR(expath);
WT_CLEAR(exconfig);
WT_RET(__wt_library_init());
WT_RET(__wt_calloc_def(NULL, 1, &conn));
conn->iface = stdc;
/*
* Immediately link the structure into the connection structure list:
* the only thing ever looked at on that list is the database name,
* and a NULL value is fine.
*/
__wt_spin_lock(NULL, &__wt_process.spinlock);
TAILQ_INSERT_TAIL(&__wt_process.connqh, conn, q);
__wt_spin_unlock(NULL, &__wt_process.spinlock);
session = conn->default_session = &conn->dummy_session;
session->iface.connection = &conn->iface;
session->name = "wiredtiger_open";
__wt_event_handler_set(session, event_handler);
/* Remaining basic initialization of the connection structure. */
WT_ERR(__wt_connection_init(conn));
/* Check the configuration strings. */
WT_ERR(__wt_config_check(
session, __wt_confchk_wiredtiger_open, config, 0));
/* Get the database home. */
WT_ERR(__conn_home(session, home, cfg));
/* Make sure no other thread of control already owns this database. */
WT_ERR(__conn_single(session, cfg));
/* Read the database-home configuration file. */
WT_ERR(__conn_config_file(session, cfg, &cbuf));
/* Read the environment variable configuration. */
WT_ERR(__conn_config_env(session, cfg));
WT_ERR(__wt_config_gets(session, cfg, "hazard_max", &cval));
conn->hazard_max = (uint32_t)cval.val;
WT_ERR(__wt_config_gets(session, cfg, "session_max", &cval));
conn->session_size = (uint32_t)cval.val + WT_NUM_INTERNAL_SESSIONS;
WT_ERR(__wt_config_gets(session, cfg, "lsm_merge", &cval));
if (cval.val)
F_SET(conn, WT_CONN_LSM_MERGE);
WT_ERR(__wt_config_gets(session, cfg, "sync", &cval));
if (cval.val)
F_SET(conn, WT_CONN_SYNC);
WT_ERR(__wt_config_gets(session, cfg, "transactional", &cval));
if (cval.val)
F_SET(conn, WT_CONN_TRANSACTIONAL);
/* Configure verbose flags. */
WT_ERR(__conn_verbose_config(session, cfg));
WT_ERR(__wt_conn_cache_pool_config(session, cfg));
WT_ERR(__wt_config_gets(session, cfg, "logging", &cval));
if (cval.val != 0)
WT_ERR(__wt_open(
session, WT_LOG_FILENAME, 1, 0, 0, &conn->log_fh));
/* Configure direct I/O and buffer alignment. */
WT_ERR(__wt_config_gets(session, cfg, "buffer_alignment", &cval));
if (cval.val == -1)
conn->buffer_alignment = WT_BUFFER_ALIGNMENT_DEFAULT;
else
conn->buffer_alignment = (size_t)cval.val;
#ifndef HAVE_POSIX_MEMALIGN
if (conn->buffer_alignment != 0)
WT_ERR_MSG(session, EINVAL,
"buffer_alignment requires posix_memalign");
#endif
/*
* Configuration: direct_io, mmap, statistics.
*/
WT_ERR(__wt_config_gets(session, cfg, "direct_io", &cval));
for (ft = directio_types; ft->name != NULL; ft++) {
ret = __wt_config_subgets(session, &cval, ft->name, &sval);
if (ret == 0) {
if (sval.val)
FLD_SET(conn->direct_io, ft->flag);
} else if (ret != WT_NOTFOUND)
goto err;
}
WT_ERR(__wt_config_gets(session, cfg, "mmap", &cval));
conn->mmap = cval.val == 0 ? 0 : 1;
WT_ERR(__wt_config_gets(session, cfg, "statistics", &cval));
conn->statistics = cval.val == 0 ? 0 : 1;
/* Load any extensions referenced in the config. */
WT_ERR(__wt_config_gets(session, cfg, "extensions", &cval));
WT_ERR(__wt_config_subinit(session, &subconfig, &cval));
while ((ret = __wt_config_next(&subconfig, &skey, &sval)) == 0) {
WT_ERR(__wt_buf_fmt(
session, &expath, "%.*s", (int)skey.len, skey.str));
if (sval.len > 0)
WT_ERR(__wt_buf_fmt(session, &exconfig,
"entry=%.*s\n", (int)sval.len, sval.str));
WT_ERR(conn->iface.load_extension(&conn->iface,
expath.data, (sval.len > 0) ? exconfig.data : NULL));
}
WT_ERR_NOTFOUND_OK(ret);
/*
* Open the connection; if that fails, the connection handle has been
* destroyed by the time the open function returns.
*/
if ((ret = __wt_connection_open(conn, cfg)) != 0) {
conn = NULL;
WT_ERR(ret);
}
/* Open the default session. */
WT_ERR(__wt_open_session(conn, 1, NULL, NULL, &conn->default_session));
session = conn->default_session;
/*
* Check on the turtle and metadata files, creating them if necessary
* (which avoids application threads racing to create the metadata file
* later).
*/
WT_ERR(__wt_meta_turtle_init(session, &exist));
if (!exist) {
/*
* We're single-threaded, but acquire the schema lock
* regardless: the lower level code checks that it is
* appropriately synchronized.
*/
WT_WITH_SCHEMA_LOCK(session,
ret = __wt_schema_create(session, WT_METADATA_URI, NULL));
WT_ERR(ret);
}
WT_ERR(__wt_metadata_open(session));
/* If there's a hot-backup file, load it. */
WT_ERR(__wt_metadata_load_backup(session));
/*
* XXX LSM initialization.
* This is structured so that it could be moved to an extension.
*/
WT_ERR(__wt_lsm_init(&conn->iface, NULL));
STATIC_ASSERT(offsetof(WT_CONNECTION_IMPL, iface) == 0);
*wt_connp = &conn->iface;
/*
* Destroying the connection on error will destroy our session handle,
* cleanup using the session handle first, then discard the connection.
*/
err: if (cbuf != NULL)
__wt_buf_free(session, cbuf);
__wt_buf_free(session, &expath);
__wt_buf_free(session, &exconfig);
if (ret != 0 && conn != NULL)
WT_TRET(__wt_connection_destroy(conn));
/* Let the server threads proceed. */
if (ret == 0)
conn->connection_initialized = 1;
return (ret);
}
/*
* wiredtiger_config_validate --
* Validate a configuration string.
*/
int
wiredtiger_config_validate(WT_SESSION *wt_session,
WT_EVENT_HANDLER *handler, const char *name, const char *config)
{
WT_CONNECTION_IMPL *conn, dummy_conn;
WT_SESSION_IMPL *session;
const WT_CONFIG_ENTRY *ep, **epp;
session = (WT_SESSION_IMPL *)wt_session;
/*
* It's a logic error to specify both a session and an event handler.
*/
if (session != NULL && handler != NULL)
WT_RET_MSG(session, EINVAL,
"wiredtiger_config_validate error handler ignored when "
"a session also specified");
/*
* If we're not given a session, but we do have an event handler, build
* a fake session/connection pair and configure the event handler.
*/
conn = NULL;
if (session == NULL && handler != NULL) {
WT_CLEAR(dummy_conn);
conn = &dummy_conn;
session = conn->default_session = &conn->dummy_session;
session->iface.connection = &conn->iface;
session->name = "wiredtiger_config_validate";
__wt_event_handler_set(session, handler);
}
if (session != NULL)
conn = S2C(session);
if (name == NULL)
WT_RET_MSG(session, EINVAL, "no name specified");
if (config == NULL)
WT_RET_MSG(session, EINVAL, "no configuration specified");
/*
* If we don't have a real connection, look for a matching name in the
* static list, otherwise look in the configuration list (which has any
* configuration information the application has added).
*/
if (session == NULL || conn == NULL || conn->config_entries == NULL)
ep = __wt_conn_config_match(name);
else {
ep = NULL;
for (epp = conn->config_entries;
*epp != NULL && (*epp)->method != NULL; ++epp)
if (strcmp((*epp)->method, name) == 0) {
ep = *epp;
break;
}
}
if (ep == NULL)
WT_RET_MSG(session, EINVAL,
"unknown or unsupported configuration API: %s",
name);
return (__wt_config_check(session, ep, config, 0));
}
/*
* __conn_config_file --
* Read in any WiredTiger_config file in the home directory.
*/
static int
__conn_config_file(WT_SESSION_IMPL *session, const char **cfg, WT_ITEM **cbufp)
{
WT_DECL_ITEM(cbuf);
WT_DECL_RET;
WT_FH *fh;
off_t size;
uint32_t len;
int exist, quoted;
uint8_t *p, *t;
*cbufp = NULL; /* Returned buffer */
fh = NULL;
/* Check for an optional configuration file. */
#define WT_CONFIGFILE "WiredTiger.config"
WT_RET(__wt_exist(session, WT_CONFIGFILE, &exist));
if (!exist)
return (0);
/* Open the configuration file. */
WT_RET(__wt_open(session, WT_CONFIGFILE, 0, 0, 0, &fh));
WT_ERR(__wt_filesize(session, fh, &size));
if (size == 0)
goto err;
/*
* Sanity test: a 100KB configuration file would be insane. (There's
* no practical reason to limit the file size, but I can either limit
* the file size to something rational, or I can add code to test if
* the off_t size is larger than a uint32_t, which is more complicated
* and a waste of time.)
*/
if (size > 100 * 1024)
WT_ERR_MSG(session, EFBIG, WT_CONFIGFILE);
len = (uint32_t)size;
/*
* Copy the configuration file into memory, with a little slop, I'm not
* interested in debugging off-by-ones.
*
* The beginning of a file is the same as if we run into an unquoted
* newline character, simplify the parsing loop by pretending that's
* what we're doing.
*/
WT_ERR(__wt_scr_alloc(session, len + 10, &cbuf));
WT_ERR(
__wt_read(session, fh, (off_t)0, len, ((uint8_t *)cbuf->mem) + 1));
((uint8_t *)cbuf->mem)[0] = '\n';
cbuf->size = len + 1;
/*
* Collapse the file's lines into a single string: newline characters
* are replaced with commas unless the newline is quoted or backslash
* escaped. Comment lines (an unescaped newline where the next non-
* white-space character is a hash), are discarded.
*/
for (quoted = 0, p = t = cbuf->mem; len > 0;) {
/*
* Backslash pairs pass through untouched, unless immediately
* preceding a newline, in which case both the backslash and
* the newline are discarded. Backslash characters escape
* quoted characters, too, that is, a backslash followed by a
* quote doesn't start or end a quoted string.
*/
if (*p == '\\' && len > 1) {
if (p[1] != '\n') {
*t++ = p[0];
*t++ = p[1];
}
p += 2;
len -= 2;
continue;
}
/*
* If we're in a quoted string, or starting a quoted string,
* take all characters, including white-space and newlines.
*/
if (quoted || *p == '"') {
if (*p == '"')
quoted = !quoted;
*t++ = *p++;
--len;
continue;
}
/* Everything else gets taken, except for newline characters. */
if (*p != '\n') {
*t++ = *p++;
--len;
continue;
}
/*
* Replace any newline characters with commas (and strings of
* commas are safe).
*
* After any newline, skip to a non-white-space character; if
* the next character is a hash mark, skip to the next newline.
*/
for (;;) {
for (*t++ = ','; --len > 0 && isspace(*++p);)
;
if (len == 0)
break;
if (*p != '#')
break;
while (--len > 0 && *++p != '\n')
;
if (len == 0)
break;
}
}
*t = '\0';
#if 0
fprintf(stderr, "file config: {%s}\n", (const char *)cbuf->data);
#endif
/* Check the configuration string. */
WT_ERR(__wt_config_check(
session, __wt_confchk_wiredtiger_open, cbuf->data, 0));
/*
* The configuration file falls between the default configuration and
* the wiredtiger_open() configuration, overriding the defaults but not
* overriding the wiredtiger_open() configuration.
*/
while (cfg[1] != NULL)
++cfg;
cfg[1] = cfg[0];
cfg[0] = cbuf->data;
*cbufp = cbuf;
if (0) {
err: if (cbuf != NULL)
__wt_buf_free(session, cbuf);
}
if (fh != NULL)
WT_TRET(__wt_close(session, fh));
return (ret);
}
/*
* __wt_configure_method --
* WT_CONNECTION.configure_method.
*/
int
__wt_configure_method(WT_SESSION_IMPL *session,
const char *method, const char *uri,
const char *config, const char *type, const char *check)
{
const WT_CONFIG_CHECK *cp;
WT_CONFIG_CHECK *checks, *newcheck;
const WT_CONFIG_ENTRY **epp;
WT_CONFIG_ENTRY *entry;
WT_CONNECTION_IMPL *conn;
WT_DECL_RET;
size_t cnt;
char *newcheck_name, *p;
/*
* !!!
* We ignore the specified uri, that is, all new configuration options
* will be valid for all data sources. That shouldn't be too bad as
* the worst that can happen is an application might specify some
* configuration option and not get an error -- the option should be
* ignored by the underlying implementation since it's unexpected, so
* there shouldn't be any real problems. Eventually I expect we will
* get the whole data-source thing sorted, at which time there may be
* configuration arrays for each data source, and that's when the uri
* will matter.
*/
WT_UNUSED(uri);
conn = S2C(session);
checks = newcheck = NULL;
entry = NULL;
newcheck_name = NULL;
/* Argument checking; we only support a limited number of types. */
if (config == NULL)
WT_RET_MSG(session, EINVAL, "no configuration specified");
if (type == NULL)
WT_RET_MSG(session, EINVAL, "no configuration type specified");
if (strcmp(type, "boolean") != 0 && strcmp(type, "int") != 0 &&
strcmp(type, "list") != 0 && strcmp(type, "string") != 0)
WT_RET_MSG(session, EINVAL,
"type must be one of \"boolean\", \"int\", \"list\" or "
"\"string\"");
/*
* Translate the method name to our configuration names, then find a
* match.
*/
for (epp = conn->config_entries;
*epp != NULL && (*epp)->method != NULL; ++epp)
if (strcmp((*epp)->method, method) == 0)
break;
if (*epp == NULL || (*epp)->method == NULL)
WT_RET_MSG(session,
WT_NOTFOUND, "no method matching %s found", method);
/*
* Technically possible for threads to race, lock the connection while
* adding the new configuration information. We're holding the lock
* for an extended period of time, but configuration changes should be
* rare and only happen during startup.
*/
__wt_spin_lock(session, &conn->api_lock);
/*
* Allocate new configuration entry and fill it in.
*
* The new base value is the previous base value, a separator and the
* new configuration string.
*/
WT_ERR(__wt_calloc_one(session, &entry));
entry->method = (*epp)->method;
WT_ERR(__wt_calloc_def(session,
strlen((*epp)->base) + strlen(",") + strlen(config) + 1, &p));
(void)strcpy(p, (*epp)->base);
(void)strcat(p, ",");
(void)strcat(p, config);
entry->base = p;
/*
* There may be a default value in the config argument passed in (for
* example, (kvs_parallelism=64"). The default value isn't part of the
* name, build a new one.
*/
WT_ERR(__wt_strdup(session, config, &newcheck_name));
if ((p = strchr(newcheck_name, '=')) != NULL)
*p = '\0';
/*
* The new configuration name may replace an existing check with new
* information, in that case skip the old version.
*/
cnt = 0;
if ((*epp)->checks != NULL)
for (cp = (*epp)->checks; cp->name != NULL; ++cp)
++cnt;
WT_ERR(__wt_calloc_def(session, cnt + 2, &checks));
cnt = 0;
if ((*epp)->checks != NULL)
for (cp = (*epp)->checks; cp->name != NULL; ++cp)
if (strcmp(newcheck_name, cp->name) != 0)
checks[cnt++] = *cp;
newcheck = &checks[cnt];
newcheck->name = newcheck_name;
WT_ERR(__wt_strdup(session, type, &newcheck->type));
WT_ERR(__wt_strdup(session, check, &newcheck->checks));
entry->checks = checks;
entry->checks_entries = 0;
/*
* Confirm the configuration string passes the new set of
* checks.
*/
WT_ERR(__wt_config_check(session, entry, config, 0));
/*
* The next time this configuration is updated, we don't want to figure
* out which of these pieces of memory were allocated and will need to
* be free'd on close (this isn't a heavily used API and it's too much
* work); add them all to the free-on-close list now. We don't check
* for errors deliberately, we'd have to figure out which elements have
* already been added to the free-on-close array and which have not in
* order to avoid freeing chunks of memory twice. Again, this isn't a
* commonly used API and it shouldn't ever happen, just leak it.
*/
__wt_conn_foc_add(session, entry->base);
__wt_conn_foc_add(session, entry);
__wt_conn_foc_add(session, checks);
__wt_conn_foc_add(session, newcheck->type);
__wt_conn_foc_add(session, newcheck->checks);
__wt_conn_foc_add(session, newcheck_name);
/*
* Instead of using locks to protect configuration information, assume
* we can atomically update a pointer to a chunk of memory, and because
* a pointer is never partially written, readers will correctly see the
* original or new versions of the memory. Readers might be using the
* old version as it's being updated, though, which means we cannot free
* the old chunk of memory until all possible readers have finished.
* Currently, that's on connection close: in other words, we can use
* this because it's small amounts of memory, and we really, really do
* not want to acquire locks every time we access configuration strings,
* since that's done on every API call.
*/
WT_PUBLISH(*epp, entry);
if (0) {
err: if (entry != NULL) {
__wt_free(session, entry->base);
__wt_free(session, entry);
}
__wt_free(session, checks);
if (newcheck != NULL) {
__wt_free(session, newcheck->type);
__wt_free(session, newcheck->checks);
}
__wt_free(session, newcheck_name);
}
__wt_spin_unlock(session, &conn->api_lock);
return (ret);
}
