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pgmemcache.c
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/*
* PostgreSQL functions to interface with memcache.
*
* Copyright (c) 2004-2005 Sean Chittenden <[email protected]>
* Copyright (c) 2007-2008 Neil Conway <[email protected]>
* Copyright (c) 2007 Open Technology Group, Inc. <http://www.otg-nc.com>
* Copyright (c) 2008-2013 Hannu Valtonen <[email protected]>
* Copyright (c) 2012-2014 Ohmu Ltd <[email protected]>
*
* See the file LICENSE for distribution terms.
*/
#ifdef USE_OMCACHE
#ifndef OMCACHE_READ_TIMEOUT
#define OMCACHE_READ_TIMEOUT 2000
#endif // !OMCACHE_READ_TIMEOUT
#define MEMCACHED_READ_TIMEOUT OMCACHE_READ_TIMEOUT
#ifndef OMCACHE_WRITE_TIMEOUT
#define OMCACHE_WRITE_TIMEOUT 20
#endif // !OMCACHE_WRITE_TIMEOUT
#define MEMCACHED_WRITE_TIMEOUT OMCACHE_WRITE_TIMEOUT
#include "omcache_libmemcached.h"
#include <syslog.h> /* for log levels */
#endif /* USE_OMCACHE */
#ifdef USE_LIBMEMCACHED
#include <libmemcached/memcached.h>
#endif /* USE_LIBMEMCACHED */
#include "pgmemcache.h"
#define KEY_MAX_LENGTH 250
#ifdef PG_MODULE_MAGIC
PG_MODULE_MAGIC;
#endif
/* Internal functions */
static void pgmemcache_reset_context(void);
static void pgmemcache_xact_callback(XactEvent event, void *arg);
static void assign_sasl_params(const char *username, const char *password);
static void assign_default_servers_guc(const char *newval, void *extra);
static void assign_default_behavior_guc(const char *newval, void *extra);
static memcached_behavior get_memcached_behavior_flag(const char *flag);
static uint64_t get_memcached_behavior_data(const char *flag, const char *data, const char **val);
static Datum memcache_set_cmd(int type, PG_FUNCTION_ARGS);
static memcached_return do_server_add(const char *host_str);
const char *get_arg_cstring(text *text_field, size_t *length, bool is_key);
/* Per-backend global state. */
static struct memcache_global_s
{
memcached_st *mc;
bool flush_needed;
bool flush_on_commit;
char *default_servers;
char *default_behavior;
char *sasl_authentication_username;
char *sasl_authentication_password;
} globals;
void _PG_init(void)
{
pgmemcache_reset_context();
DefineCustomStringVariable("pgmemcache.default_servers",
"Comma-separated list of memcached servers to connect to.",
"Specified as a comma-separated list of host:port (port is optional).",
&globals.default_servers,
NULL,
PGC_USERSET,
GUC_LIST_INPUT,
#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 90100)
NULL,
#endif
assign_default_servers_guc,
NULL);
DefineCustomStringVariable("pgmemcache.default_behavior",
"Comma-separated list of memcached behavior (optional).",
"Specified as a comma-separated list of behavior_flag:behavior_data.",
&globals.default_behavior,
NULL,
PGC_USERSET,
GUC_LIST_INPUT,
#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 90100)
NULL,
#endif
assign_default_behavior_guc,
NULL);
DefineCustomBoolVariable("pgmemcache.flush_on_commit",
"Whether to flush all buffers to memcached on end of commit",
NULL,
&globals.flush_on_commit,
false,
PGC_USERSET,
0,
#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 90100)
NULL,
#endif
NULL,
NULL);
DefineCustomStringVariable("pgmemcache.sasl_authentication_username",
"pgmemcache SASL user authentication username",
"Simple string pgmemcache.sasl_authentication_username = 'testing_username'",
&globals.sasl_authentication_username,
NULL,
PGC_USERSET,
GUC_LIST_INPUT,
#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 90100)
NULL,
#endif
NULL,
NULL);
DefineCustomStringVariable("pgmemcache.sasl_authentication_password",
"pgmemcache SASL user authentication password",
"Simple string pgmemcache.sasl_authentication_password = 'testing_password'",
&globals.sasl_authentication_password,
NULL,
PGC_USERSET,
GUC_LIST_INPUT,
#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 90100)
NULL,
#endif
NULL,
NULL);
/* XXX: We should have real assign_hook for these so that memcache sasl data
* is updated when the values are changed. */
assign_sasl_params(globals.sasl_authentication_username, globals.sasl_authentication_password);
RegisterXactCallback(pgmemcache_xact_callback, NULL);
}
/* This is called when we're being unloaded from a process. Note that
* this only happens when we're being replaced by a LOAD (e.g. it
* doesn't happen on process exit), so we can't depend on it being
* called. */
void _PG_fini(void)
{
memcached_free(globals.mc);
}
static time_t interval_to_time_t(Interval *span)
{
float8 result;
#ifdef HAVE_INT64_TIMESTAMP
result = span->time / 1000000e0;
#else
result = span->time;
#endif
result += span->day * 86400;
if (span->month != 0)
{
result += (365.25 * 86400) * (span->month / 12);
result += (30.0 * 86400) * (span->month % 12);
}
return (time_t) result;
}
/* called at end of transaction, flush all buffers to memcache */
static void pgmemcache_xact_callback(XactEvent event, void *arg)
{
if (globals.flush_on_commit && globals.flush_needed &&
(event == XACT_EVENT_COMMIT
#if defined(PG_VERSION_NUM) && (PG_VERSION_NUM >= 90300)
|| event == XACT_EVENT_PRE_COMMIT
#endif /* PG_VERSION_NUM >= 90300 */
))
{
#ifdef USE_LIBMEMCACHED
memcached_return rc = memcached_flush_buffers(globals.mc);
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
int rc = omcache_io(globals.mc, NULL, NULL, NULL, NULL, OMCACHE_READ_TIMEOUT);
#endif /* USE_OMCACHE */
if (rc != MEMCACHED_SUCCESS)
elog(WARNING, "pgmemcache: memcached_flush_buffers: %s",
memcached_strerror(globals.mc, rc));
else
globals.flush_needed = false;
}
}
#ifdef USE_OMCACHE
static void pgmemcache_log_func(void *context, int syslog_level, const char *msg)
{
int pg_level = LOG_INFO;
switch (syslog_level)
{
case LOG_ERR:
case LOG_WARNING: pg_level = WARNING; break;
case LOG_NOTICE: pg_level = NOTICE; break;
}
elog(pg_level, "%s", msg);
}
#endif /* USE_OMCACHE */
static void pgmemcache_reset_context(void)
{
if (globals.mc)
{
memcached_free(globals.mc);
globals.mc = NULL;
}
globals.mc = memcached_create(NULL);
#ifdef USE_OMCACHE
omcache_set_log_callback(globals.mc, 0, pgmemcache_log_func, NULL);
#endif /* USE_OMCACHE */
#ifdef USE_LIBMEMCACHED
/* Always use the memcache binary protocol as required for
memcached_(increment|decrement)_with_initial. */
{
int rc = memcached_behavior_set(globals.mc,
MEMCACHED_BEHAVIOR_BINARY_PROTOCOL,
1);
if (rc != MEMCACHED_SUCCESS)
elog(WARNING, "pgmemcache: memcached_behavior_set(BINARY_PROTOCOL, 1): %s",
memcached_strerror(globals.mc, rc));
}
#endif /* USE_LIBMEMCACHED */
assign_default_behavior_guc(globals.default_behavior, NULL);
assign_sasl_params(globals.sasl_authentication_username, globals.sasl_authentication_password);
}
static void assign_sasl_params(const char *username, const char *password)
{
#if LIBMEMCACHED_WITH_SASL_SUPPORT
if (username != NULL && strlen(username) > 0 && password != NULL && strlen(password) > 0)
{
int rc = memcached_set_sasl_auth_data(globals.mc, username, password);
if (rc != MEMCACHED_SUCCESS)
elog(ERROR, "pgmemcache: memcached_set_sasl_auth_data: %s",
memcached_strerror(globals.mc, rc));
rc = sasl_client_init(NULL);
if (rc != SASL_OK)
elog(ERROR, "pgmemcache: sasl_client_init failed: %d", rc);
}
#endif
}
static void assign_default_servers_guc(const char *newval, void *extra)
{
if (newval)
{
#ifdef USE_LIBMEMCACHED
/* there is no way to remove servers from a memcache context, so
* recreate it from scratch when the server list changes */
pgmemcache_reset_context();
#endif /* USE_LIBMEMCACHED */
do_server_add(newval);
}
}
static void assign_default_behavior_guc(const char *newval, void *extra)
{
int i, len;
StringInfoData flag_buf;
StringInfoData data_buf;
memcached_return rc;
memcached_behavior bkey;
uint64_t bval;
const char *bvalstr = "";
if (!newval)
return;
initStringInfo(&flag_buf);
initStringInfo(&data_buf);
len = strlen(newval);
for (i = 0; i < len; i++)
{
char c = newval[i];
if (c == ',' || c == ':')
{
if (flag_buf.len == 0)
return;
if (c == ':')
{
int j;
for (j = i + 1; j < len; j++)
{
if (newval[j] == ',')
break;
appendStringInfoChar(&data_buf, newval[j]);
}
if (data_buf.len == 0)
return;
i += data_buf.len;
}
rc = MEMCACHED_FAILURE;
bkey = get_memcached_behavior_flag(flag_buf.data);
bval = get_memcached_behavior_data(flag_buf.data, data_buf.data, &bvalstr);
#ifdef USE_OMCACHE
if (bkey == NULL)
rc = OMCACHE_FAIL;
else if (strcmp(bkey, "BINARY_PROTOCOL") == 0)
{
if (!bval)
elog(ERROR, "pgmemcache: omcache always uses binary protocol");
rc = OMCACHE_OK;
}
else if (strcmp(bkey, "BUFFER_REQUESTS") == 0)
rc = omcache_set_buffering(globals.mc, bval);
else if (strcmp(bkey, "CONNECT_TIMEOUT") == 0)
rc = omcache_set_connect_timeout(globals.mc, bval);
else if (strcmp(bkey, "DEAD_TIMEOUT") == 0)
rc = omcache_set_dead_timeout(globals.mc, bval * 1000);
else if (strcmp(bkey, "DISTRIBUTION") == 0)
{
if (strcmp(bvalstr, "CONSISTENT") && strcmp(bvalstr, "CONSISTENT_KETAMA"))
elog(ERROR, "pgmemcache: omcache always uses ketama");
rc = OMCACHE_OK;
}
else if (strcmp(bkey, "HASH") == 0 || strcmp(bkey, "KETAMA_HASH") == 0)
{
if (strcmp(bvalstr, "DEFAULT"))
elog(ERROR, "pgmemcache: omcache always uses the 'default' (bob jenkins' 'one at a time') hash");
rc = OMCACHE_OK;
}
else if (strcmp(bkey, "KETAMA") == 0)
{
if (!bval)
elog(ERROR, "pgmemcache: omcache always uses a ketama distribution method");
rc = omcache_set_distribution_method(globals.mc, &omcache_dist_libmemcached_ketama);
}
else if (strcmp(bkey, "KETAMA_WEIGHTED") == 0)
{
if (!bval)
elog(ERROR, "pgmemcache: omcache always uses a ketama distribution method");
rc = omcache_set_distribution_method(globals.mc, &omcache_dist_libmemcached_ketama_weighted);
}
else if (strcmp(bkey, "KETAMA_PRE1010") == 0)
{
if (!bval)
elog(ERROR, "pgmemcache: omcache always uses a ketama distribution method");
rc = omcache_set_distribution_method(globals.mc, &omcache_dist_libmemcached_ketama_pre1010);
}
else if (strcmp(bkey, "NO_BLOCK") == 0)
rc = OMCACHE_OK; // omcache is non-blocking by default
else if (strcmp(bkey, "NOREPLY") == 0)
rc = OMCACHE_OK; // this isn't really a behavior in omcache
else if (strcmp(bkey, "REMOVE_FAILED_SERVERS") == 0)
rc = OMCACHE_OK; // omcache doesn't have this concept
else if (strcmp(bkey, "RETRY_TIMEOUT") == 0)
rc = omcache_set_reconnect_timeout(globals.mc, bval * 1000);
else if (strcmp(bkey, "SUPPORT_CAS") == 0)
rc = OMCACHE_OK; // omcache uses binary protocol which always has cas
else
{
elog(ERROR, "pgmemcache: unsupported behavior %s for omcache", flag_buf.data);
}
#endif /* USE_OMCACHE */
#ifdef USE_LIBMEMCACHED
rc = memcached_behavior_set(globals.mc, bkey, bval);
#endif /* USE_LIBMEMCACHED */
if (rc != MEMCACHED_SUCCESS)
elog(WARNING, "pgmemcache: memcached_behavior_set: %s",
memcached_strerror(globals.mc, rc));
/* Skip the element separator, reset buffers */
i++;
flag_buf.data[0] = '\0';
flag_buf.len = 0;
data_buf.data[0] = '\0';
data_buf.len = 0;
}
else
{
appendStringInfoChar(&flag_buf, c);
}
}
pfree(flag_buf.data);
pfree(data_buf.data);
}
Datum memcache_add(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_ADD | PG_MEMCACHE_TYPE_INTERVAL, fcinfo);
}
Datum memcache_add_absexpire(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_ADD | PG_MEMCACHE_TYPE_TIMESTAMP, fcinfo);
}
const char *get_arg_cstring(text *text_field, size_t *length, bool is_key)
{
*length = VARSIZE(text_field) - VARHDRSZ;
if (is_key && *length < 1)
elog(ERROR, "pgmemcache: key cannot be an empty string");
else if (is_key && *length > KEY_MAX_LENGTH)
elog(ERROR, "pgmemcache: key too long, maximum is %d characters", KEY_MAX_LENGTH);
return VARDATA(text_field);
}
static Datum memcache_delta_op(bool increment, PG_FUNCTION_ARGS)
{
uint64_t val;
int64_t offset = 1;
memcached_return rc;
size_t key_length;
const char *key = get_arg_cstring(PG_GETARG_TEXT_P(0), &key_length, true);
if (PG_NARGS() >= 2)
offset = PG_GETARG_INT64(1);
if (offset < 0)
{
/* memcached uses uint64_t but postgresql only has signed types, but
* since we have both increment and decrement operations let's just
* invert the operation if offset is negative.
*/
offset = abs(offset);
increment = !increment;
}
if (increment)
rc = memcached_increment_with_initial(globals.mc, key, key_length, offset, 0, MEMCACHED_EXPIRATION_NOT_ADD, &val);
else
rc = memcached_decrement_with_initial(globals.mc, key, key_length, offset, 0, MEMCACHED_EXPIRATION_NOT_ADD, &val);
if (rc == MEMCACHED_BUFFERED)
{
globals.flush_needed = true;
PG_RETURN_NULL();
}
if (rc != MEMCACHED_SUCCESS)
{
elog(WARNING, "pgmemcache: memcached_%s_with_initial: %s",
increment ? "increment" : "decrement",
memcached_strerror(globals.mc, rc));
}
else if (val > 0x7FFFFFFFFFFFFFFFLL && val != UINT64_MAX)
{
/* Cannot represent uint64_t values above 2^63-1 with BIGINT. Do
not signal error for UINT64_MAX which just means there was no
reply. */
elog(ERROR, "pgmemcache: memcached_%s_with_initial: %s",
increment ? "increment" : "decrement",
"value received from memcache is out of BIGINT range");
}
PG_RETURN_INT64(val);
}
Datum memcache_decr(PG_FUNCTION_ARGS)
{
return memcache_delta_op(false, fcinfo);
}
Datum memcache_incr(PG_FUNCTION_ARGS)
{
return memcache_delta_op(true, fcinfo);
}
Datum memcache_delete(PG_FUNCTION_ARGS)
{
time_t hold;
memcached_return rc;
size_t key_length;
const char *key = get_arg_cstring(PG_GETARG_TEXT_P(0), &key_length, true);
hold = (time_t) 0.0;
if (PG_NARGS() >= 2 && PG_ARGISNULL(1) == false)
hold = interval_to_time_t(PG_GETARG_INTERVAL_P(1));
rc = memcached_delete(globals.mc, key, key_length, hold);
if (rc == MEMCACHED_BUFFERED)
{
globals.flush_needed = true;
PG_RETURN_NULL();
}
if (rc != MEMCACHED_SUCCESS && rc != MEMCACHED_NOTFOUND)
elog(WARNING, "pgmemcache: memcached_delete: %s",
memcached_strerror(globals.mc, rc));
PG_RETURN_BOOL(rc == MEMCACHED_SUCCESS);
}
Datum memcache_flush_all0(PG_FUNCTION_ARGS)
{
static time_t opt_expire = 0;
memcached_return rc;
rc = memcached_flush(globals.mc, opt_expire);
if (rc == MEMCACHED_BUFFERED)
{
globals.flush_needed = true;
PG_RETURN_NULL();
}
if (rc != MEMCACHED_SUCCESS)
elog(WARNING, "pgmemcache: memcached_flush: %s",
memcached_strerror(globals.mc, rc));
PG_RETURN_BOOL(rc == MEMCACHED_SUCCESS);
}
Datum memcache_get(PG_FUNCTION_ARGS)
{
text *ret;
#ifdef USE_LIBMEMCACHED
char *string;
uint32_t flags;
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
const unsigned char *string;
#endif /* USE_OMCACHE */
size_t return_value_length;
memcached_return rc;
size_t key_length;
const char *key = get_arg_cstring(PG_GETARG_TEXT_P(0), &key_length, true);
#ifdef USE_LIBMEMCACHED
string = memcached_get(globals.mc, key, key_length, &return_value_length, &flags, &rc);
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
rc = omcache_get(globals.mc, omc_cc_to_cuc(key), key_length, &string, &return_value_length,
NULL, NULL, OMCACHE_READ_TIMEOUT);
#endif /* USE_OMCACHE */
if (rc != MEMCACHED_SUCCESS && rc != MEMCACHED_NOTFOUND)
elog(ERROR, "pgmemcache: memcached_get: %s",
memcached_strerror(globals.mc, rc));
if (rc == MEMCACHED_NOTFOUND)
PG_RETURN_NULL();
ret = (text *) palloc(return_value_length + VARHDRSZ);
SET_VARSIZE(ret, return_value_length + VARHDRSZ);
memcpy(VARDATA(ret), string, return_value_length);
#ifdef USE_LIBMEMCACHED
free(string);
#endif /* USE_LIBMEMCACHED */
PG_RETURN_TEXT_P(ret);
}
Datum memcache_get_multi(PG_FUNCTION_ARGS)
{
ArrayType *array;
int array_length, array_lbound, i;
Oid element_type;
memcached_return rc;
char typalign;
int16 typlen;
bool typbyval;
#ifdef USE_LIBMEMCACHED
uint32_t flags;
char *current_key, *current_val;
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
const unsigned char *current_key, *current_val;
#endif /* USE_OMCACHE */
size_t current_key_len, current_val_len;
FuncCallContext *funcctx;
MemoryContext oldcontext;
TupleDesc tupdesc;
AttInMetadata *attinmeta;
struct internal_fctx {
size_t *key_lens;
#ifdef USE_LIBMEMCACHED
const char **keys;
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
const unsigned char **keys;
omcache_req_t *requests;
size_t request_count;
omcache_value_t *values;
size_t value_count;
#endif /* USE_OMCACHE */
} *fctx;
array = PG_GETARG_ARRAYTYPE_P(0);
if (ARR_NDIM(array) != 1)
elog(ERROR, "pgmemcache: only single dimension ARRAYs are supported, "
"not ARRAYs with %d dimensions", ARR_NDIM(array));
array_lbound = ARR_LBOUND(array)[0];
array_length = ARR_DIMS(array)[0];
element_type = ARR_ELEMTYPE(array);
if (SRF_IS_FIRSTCALL())
{
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
funcctx->max_calls = array_length;
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("function returning record called in context that cannot accept type record")));
get_typlenbyvalalign(element_type, &typlen, &typbyval, &typalign);
fctx = (struct internal_fctx *) palloc(sizeof(*fctx));
/* extra NULL key for last memcached_fetch call */
fctx->keys = palloc(sizeof(char *) * (array_length + 1));
fctx->key_lens = palloc(sizeof(size_t) * (array_length + 1));
fctx->keys[array_length] = 0;
fctx->key_lens[array_length] = 0;
#ifdef USE_LIBMEMCACHED
for (i = 0; i < array_length; i++)
{
int offset = array_lbound + i;
bool isnull;
Datum elem = array_ref(array, 1, &offset, 0, typlen, typbyval, typalign, &isnull);
if (!isnull)
fctx->keys[i] = get_arg_cstring(DatumGetTextP(elem), &fctx->key_lens[i], true);
}
rc = memcached_mget(globals.mc, fctx->keys, fctx->key_lens, array_length);
if (rc != MEMCACHED_SUCCESS)
elog(ERROR, "pgmemcache: memcached_mget: %s",
memcached_strerror(globals.mc, rc));
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
/* persistent request structures to handle pending requests */
fctx->requests = palloc(sizeof(omcache_req_t) * array_length);
fctx->request_count = array_length;
fctx->values = palloc(sizeof(omcache_value_t) * array_length);
fctx->value_count = array_length;
for (i = 0; i < array_length; i++)
{
int offset = array_lbound + i;
bool isnull;
Datum elem = array_ref(array, 1, &offset, 0, typlen, typbyval, typalign, &isnull);
if (!isnull)
fctx->keys[i] = (const unsigned char *)
get_arg_cstring(DatumGetTextP(elem), &fctx->key_lens[i], true);
}
rc = omcache_get_multi(globals.mc, fctx->keys, fctx->key_lens, array_length,
fctx->requests, &fctx->request_count, fctx->values, &fctx->value_count,
OMCACHE_READ_TIMEOUT);
if (rc != OMCACHE_OK && rc != OMCACHE_AGAIN)
elog(ERROR, "pgmemcache: omcache_get_multi: %s", omcache_strerror(rc));
#endif /* USE_OMCACHE */
attinmeta = TupleDescGetAttInMetadata(tupdesc);
funcctx->attinmeta = attinmeta;
funcctx->user_fctx = fctx;
MemoryContextSwitchTo(oldcontext);
}
funcctx = SRF_PERCALL_SETUP();
fctx = funcctx->user_fctx;
attinmeta = funcctx->attinmeta;
#ifdef USE_LIBMEMCACHED
current_key = (char *) fctx->keys[funcctx->call_cntr]; // cast away constness for libmemcached api
current_key_len = fctx->key_lens[funcctx->call_cntr];
current_val = memcached_fetch(globals.mc, current_key, ¤t_key_len, ¤t_val_len, &flags, &rc);
if (rc == MEMCACHED_END)
{
SRF_RETURN_DONE(funcctx);
}
else if (rc != MEMCACHED_SUCCESS)
{
elog(ERROR, "pgmemcache: memcached_fetch: %s",
memcached_strerror(globals.mc, rc));
SRF_RETURN_DONE(funcctx);
}
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
current_val = NULL;
if (fctx->value_count == 0 && fctx->request_count > 0)
{
fctx->value_count = fctx->request_count;
rc = omcache_io(globals.mc, fctx->requests, &fctx->request_count,
fctx->values, &fctx->value_count, OMCACHE_READ_TIMEOUT);
if (rc != OMCACHE_OK && rc != OMCACHE_AGAIN)
elog(ERROR, "pgmemcache: omcache_io: %s", omcache_strerror(rc));
}
if (fctx->value_count > 0)
{
fctx->value_count --;
current_key = fctx->values[fctx->value_count].key;
current_key_len = fctx->values[fctx->value_count].key_len;
current_val = fctx->values[fctx->value_count].data;
current_val_len = fctx->values[fctx->value_count].data_len;
}
#endif /* USE_OMCACHE */
if (current_val != NULL)
{
char **values;
HeapTuple tuple;
Datum result;
values = (char **) palloc(2 * sizeof(char *));
/* make sure we have space for terminating zero character */
values[0] = (char *) palloc(current_key_len + 1);
values[1] = (char *) palloc(current_val_len + 1);
memcpy(values[0], current_key, current_key_len);
memcpy(values[1], current_val, current_val_len);
#ifdef USE_LIBMEMCACHED
free(current_val);
#endif /* USE_LIBMEMCACHED */
/* BuildTupleFromCStrings needs correct zero-terminated C-string, so terminate our raw strings */
values[0][current_key_len] = '\0';
values[1][current_val_len] = '\0';
tuple = BuildTupleFromCStrings(attinmeta, values);
result = HeapTupleGetDatum(tuple);
SRF_RETURN_NEXT(funcctx, result);
}
SRF_RETURN_DONE(funcctx);
}
Datum memcache_replace(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_REPLACE | PG_MEMCACHE_TYPE_INTERVAL, fcinfo);
}
Datum memcache_replace_absexpire(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_REPLACE | PG_MEMCACHE_TYPE_TIMESTAMP, fcinfo);
}
Datum memcache_set(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_SET | PG_MEMCACHE_TYPE_INTERVAL, fcinfo);
}
Datum memcache_set_absexpire(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_SET | PG_MEMCACHE_TYPE_TIMESTAMP, fcinfo);
}
Datum memcache_prepend(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_PREPEND | PG_MEMCACHE_TYPE_INTERVAL, fcinfo);
}
Datum memcache_prepend_absexpire(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_PREPEND | PG_MEMCACHE_TYPE_TIMESTAMP, fcinfo);
}
Datum memcache_append(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_APPEND | PG_MEMCACHE_TYPE_INTERVAL, fcinfo);
}
Datum memcache_append_absexpire(PG_FUNCTION_ARGS)
{
return memcache_set_cmd(PG_MEMCACHE_CMD_APPEND | PG_MEMCACHE_TYPE_TIMESTAMP, fcinfo);
}
static Datum memcache_set_cmd(int type, PG_FUNCTION_ARGS)
{
memcached_return rc = MEMCACHED_FAILURE;
const char *func = NULL;
time_t expiration = 0;
size_t key_length, value_length;
const char *key = get_arg_cstring(PG_GETARG_TEXT_P(0), &key_length, true);
const char *value = get_arg_cstring(PG_GETARG_TEXT_P(1), &value_length, false);
if (PG_NARGS() >= 3 && PG_ARGISNULL(2) == false)
{
if (type & PG_MEMCACHE_TYPE_INTERVAL)
{
Interval *span = PG_GETARG_INTERVAL_P(2);
expiration = interval_to_time_t(span);
}
else if (type & PG_MEMCACHE_TYPE_TIMESTAMP)
{
TimestampTz timestamptz;
struct pg_tm tm;
fsec_t fsec;
timestamptz = PG_GETARG_TIMESTAMPTZ(2);
/* convert to timestamptz to produce consistent results */
if (timestamp2tm(timestamptz, NULL, &tm, &fsec, NULL, NULL) !=0)
ereport(ERROR,
(errcode(ERRCODE_DATETIME_VALUE_OUT_OF_RANGE),
errmsg("timestamp out of range")));
#ifdef HAVE_INT64_TIMESTAMP
expiration = (time_t) ((timestamptz - SetEpochTimestamp()) / 1000000e0);
#else
expiration = (time_t) timestamptz - SetEpochTimestamp();
#endif
}
else
{
elog(ERROR, "%s():%s:%u: invalid date type", __FUNCTION__, __FILE__, __LINE__);
}
}
switch (type & PG_MEMCACHE_CMD_MASK)
{
case PG_MEMCACHE_CMD_ADD:
func = "memcached_add";
rc = memcached_add(globals.mc, key, key_length, value, value_length, expiration, 0);
break;
case PG_MEMCACHE_CMD_REPLACE:
func = "memcached_replace";
rc = memcached_replace(globals.mc, key, key_length, value, value_length, expiration, 0);
break;
case PG_MEMCACHE_CMD_SET:
func = "memcached_set";
rc = memcached_set(globals.mc, key, key_length, value, value_length, expiration, 0);
break;
case PG_MEMCACHE_CMD_PREPEND:
func = "memcached_prepend";
rc = memcached_prepend(globals.mc, key, key_length, value, value_length, expiration, 0);
break;
case PG_MEMCACHE_CMD_APPEND:
func = "memcached_append";
rc = memcached_append(globals.mc, key, key_length, value, value_length, expiration, 0);
break;
default:
elog(ERROR, "pgmemcache: unknown set command type: %d", type);
}
if (rc == MEMCACHED_BUFFERED)
{
globals.flush_needed = true;
PG_RETURN_NULL();
}
if (rc != MEMCACHED_SUCCESS)
elog(WARNING, "pgmemcache: %s: %s", func,
memcached_strerror(globals.mc, rc));
PG_RETURN_BOOL(rc == MEMCACHED_SUCCESS);
}
Datum memcache_server_add(PG_FUNCTION_ARGS)
{
size_t host_len;
const char *host_buf = get_arg_cstring(PG_GETARG_TEXT_P(0), &host_len, false);
char *host = pnstrdup(host_buf, host_len);
memcached_return rc = do_server_add(host);
if (rc != MEMCACHED_SUCCESS)
elog(WARNING, "pgmemcache: memcached_server_push: %s",
memcached_strerror(globals.mc, rc));
PG_RETURN_BOOL(rc == MEMCACHED_SUCCESS);
}
static memcached_return do_server_add(const char *host_str)
{
memcached_server_st *servers;
memcached_return rc;
servers = memcached_servers_parse(host_str);
rc = memcached_server_push(globals.mc, servers);
memcached_server_list_free(servers);
return rc;
}
#ifdef USE_LIBMEMCACHED
#define MC_ENUM_INVAL -1
#define MC_STR_TO_ENUM(d,v) \
if (strcmp(value, "MEMCACHED_" #d "_" #v) == 0 || strcmp(value, #v) == 0) \
return MEMCACHED_##d##_##v
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
#define MC_ENUM_INVAL NULL
#define MC_STR_TO_ENUM(d,v) \
if (strcmp(value, "MEMCACHED_" #d "_" #v) == 0 || strcmp(value, #v) == 0) \
return #v
#endif /* USE_OMCACHE */
static memcached_behavior get_memcached_behavior_flag(const char *value)
{
MC_STR_TO_ENUM(BEHAVIOR, BINARY_PROTOCOL);
MC_STR_TO_ENUM(BEHAVIOR, BUFFER_REQUESTS);
MC_STR_TO_ENUM(BEHAVIOR, CACHE_LOOKUPS);
MC_STR_TO_ENUM(BEHAVIOR, CONNECT_TIMEOUT);
#if LIBMEMCACHED_VERSION_HEX >= 0x01000003
MC_STR_TO_ENUM(BEHAVIOR, DEAD_TIMEOUT);
#endif
MC_STR_TO_ENUM(BEHAVIOR, DISTRIBUTION);
MC_STR_TO_ENUM(BEHAVIOR, HASH);
MC_STR_TO_ENUM(BEHAVIOR, HASH_WITH_PREFIX_KEY);
MC_STR_TO_ENUM(BEHAVIOR, IO_BYTES_WATERMARK);
MC_STR_TO_ENUM(BEHAVIOR, IO_KEY_PREFETCH);
MC_STR_TO_ENUM(BEHAVIOR, IO_MSG_WATERMARK);
MC_STR_TO_ENUM(BEHAVIOR, KETAMA);
MC_STR_TO_ENUM(BEHAVIOR, KETAMA_HASH);
#ifdef USE_OMCACHE
MC_STR_TO_ENUM(BEHAVIOR, KETAMA_PRE1010);
#endif
MC_STR_TO_ENUM(BEHAVIOR, KETAMA_WEIGHTED);
MC_STR_TO_ENUM(BEHAVIOR, NO_BLOCK);
MC_STR_TO_ENUM(BEHAVIOR, NOREPLY);
MC_STR_TO_ENUM(BEHAVIOR, NUMBER_OF_REPLICAS);
MC_STR_TO_ENUM(BEHAVIOR, POLL_TIMEOUT);
MC_STR_TO_ENUM(BEHAVIOR, RANDOMIZE_REPLICA_READ);
MC_STR_TO_ENUM(BEHAVIOR, RCV_TIMEOUT);
#if LIBMEMCACHED_VERSION_HEX >= 0x00049000
MC_STR_TO_ENUM(BEHAVIOR, REMOVE_FAILED_SERVERS);
#endif
MC_STR_TO_ENUM(BEHAVIOR, RETRY_TIMEOUT);
MC_STR_TO_ENUM(BEHAVIOR, SERVER_FAILURE_LIMIT);
MC_STR_TO_ENUM(BEHAVIOR, SND_TIMEOUT);
MC_STR_TO_ENUM(BEHAVIOR, SOCKET_RECV_SIZE);
MC_STR_TO_ENUM(BEHAVIOR, SOCKET_SEND_SIZE);
MC_STR_TO_ENUM(BEHAVIOR, SORT_HOSTS);
MC_STR_TO_ENUM(BEHAVIOR, SUPPORT_CAS);
MC_STR_TO_ENUM(BEHAVIOR, TCP_NODELAY);
MC_STR_TO_ENUM(BEHAVIOR, USER_DATA);
MC_STR_TO_ENUM(BEHAVIOR, USE_UDP);
MC_STR_TO_ENUM(BEHAVIOR, VERIFY_KEY);
elog(ERROR, "pgmemcache: unknown behavior flag: %s", value);
return MC_ENUM_INVAL;
}
static memcached_hash get_memcached_hash_type(const char *value)
{
MC_STR_TO_ENUM(HASH, MURMUR);
MC_STR_TO_ENUM(HASH, MD5);
MC_STR_TO_ENUM(HASH, JENKINS);
MC_STR_TO_ENUM(HASH, HSIEH);
MC_STR_TO_ENUM(HASH, FNV1A_64);
MC_STR_TO_ENUM(HASH, FNV1A_32);
MC_STR_TO_ENUM(HASH, FNV1_64);
MC_STR_TO_ENUM(HASH, FNV1_32);
MC_STR_TO_ENUM(HASH, DEFAULT);
MC_STR_TO_ENUM(HASH, CRC);
elog(ERROR, "pgmemcache: invalid hash name: %s", value);
return MC_ENUM_INVAL;
}
static memcached_server_distribution get_memcached_distribution_type(const char *value)
{
MC_STR_TO_ENUM(DISTRIBUTION, RANDOM);
MC_STR_TO_ENUM(DISTRIBUTION, MODULA);
MC_STR_TO_ENUM(DISTRIBUTION, CONSISTENT_KETAMA);
MC_STR_TO_ENUM(DISTRIBUTION, CONSISTENT);
elog(ERROR, "pgmemcache: invalid distribution name: %s", value);
return MC_ENUM_INVAL;
}
static uint64_t get_memcached_behavior_data(const char *flag, const char *data, const char **val)
{
char *endptr;
uint64_t ret;
memcached_behavior bkey = get_memcached_behavior_flag(flag);
#ifdef USE_LIBMEMCACHED
switch (bkey)
{
case MEMCACHED_BEHAVIOR_HASH:
case MEMCACHED_BEHAVIOR_KETAMA_HASH:
return get_memcached_hash_type(data);
case MEMCACHED_BEHAVIOR_DISTRIBUTION:
return get_memcached_distribution_type(data);
default:
#endif /* USE_LIBMEMCACHED */
#ifdef USE_OMCACHE
ret = 0;
if (strcmp(bkey, "HASH") == 0 || strcmp(bkey, "KETAMA_HASH") == 0)
*val = get_memcached_hash_type(data);
else if (strcmp(bkey, "DISTRIBUTION") == 0)
*val = get_memcached_distribution_type(data);
else
{
#endif /* USE_OMCACHE */
ret = strtol(data, &endptr, 10);
if (endptr == data)
elog(ERROR, "pgmemcache: invalid behavior param %s: %s", flag, data);
}
return ret;
}
/* NOTE: memcached_server_fn specifies that the first argument is const, but
* memcached_stat_get_keys wants a non-const argument so we don't define it
* as const here.
*/
static memcached_return_t server_stat_function(memcached_st *mc,
memcached_server_instance_st server,
void *context)