greenplumn streamutil 源码
greenplumn streamutil 代码
文件路径：/src/bin/pg_basebackup/streamutil.c
/*-------------------------------------------------------------------------
*
* streamutil.c - utility functions for pg_basebackup, pg_receivewal and
* pg_recvlogical
*
* Author: Magnus Hagander <magnus@hagander.net>
*
* Portions Copyright (c) 1996-2019, PostgreSQL Global Development Group
*
* IDENTIFICATION
* src/bin/pg_basebackup/streamutil.c
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include <sys/time.h>
#include <unistd.h>
/* local includes */
#include "receivelog.h"
#include "streamutil.h"
#include "access/xlog_internal.h"
#include "common/fe_memutils.h"
#include "common/file_perm.h"
#include "common/logging.h"
#include "datatype/timestamp.h"
#include "fe_utils/connect.h"
#include "port/pg_bswap.h"
#include "pqexpbuffer.h"
#define ERRCODE_DUPLICATE_OBJECT "42710"
uint32 WalSegSz;
static bool RetrieveDataDirCreatePerm(PGconn *conn);
/* SHOW command for replication connection was introduced in version 10 */
#define MINIMUM_VERSION_FOR_SHOW_CMD 100000
/*
* Group access is supported from version 11.
*/
#define MINIMUM_VERSION_FOR_GROUP_ACCESS 110000
const char *progname;
char *connection_string = NULL;
char *dbhost = NULL;
char *dbuser = NULL;
char *dbport = NULL;
char *dbname = NULL;
int dbgetpassword = 0; /* 0=auto, -1=never, 1=always */
static bool have_password = false;
static char password[100];
PGconn *conn = NULL;
/*
* Connect to the server. Returns a valid PGconn pointer if connected,
* or NULL on non-permanent error. On permanent error, the function will
* call exit(1) directly.
*/
PGconn *
GetConnection(void)
{
PGconn *tmpconn;
int argcount = 7; /* dbname, replication, fallback_app_name,
* host, user, port, password */
int i;
const char **keywords;
const char **values;
const char *tmpparam;
bool need_password;
PQconninfoOption *conn_opts = NULL;
PQconninfoOption *conn_opt;
char *err_msg = NULL;
/* pg_recvlogical uses dbname only; others use connection_string only. */
Assert(dbname == NULL || connection_string == NULL);
/*
* Merge the connection info inputs given in form of connection string,
* options and default values (dbname=replication, replication=true, etc.)
* Explicitly discard any dbname value in the connection string;
* otherwise, PQconnectdbParams() would interpret that value as being
* itself a connection string.
*/
i = 0;
if (connection_string)
{
conn_opts = PQconninfoParse(connection_string, &err_msg);
if (conn_opts == NULL)
{
pg_log_error("%s", err_msg);
exit(1);
}
for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
{
if (conn_opt->val != NULL && conn_opt->val[0] != '\0' &&
strcmp(conn_opt->keyword, "dbname") != 0)
argcount++;
}
keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
values = pg_malloc0((argcount + 1) * sizeof(*values));
for (conn_opt = conn_opts; conn_opt->keyword != NULL; conn_opt++)
{
if (conn_opt->val != NULL && conn_opt->val[0] != '\0' &&
strcmp(conn_opt->keyword, "dbname") != 0)
{
keywords[i] = conn_opt->keyword;
values[i] = conn_opt->val;
i++;
}
}
}
else
{
keywords = pg_malloc0((argcount + 1) * sizeof(*keywords));
values = pg_malloc0((argcount + 1) * sizeof(*values));
}
keywords[i] = "dbname";
values[i] = dbname == NULL ? "replication" : dbname;
i++;
keywords[i] = "replication";
values[i] = dbname == NULL ? "true" : "database";
i++;
keywords[i] = "fallback_application_name";
values[i] = progname;
i++;
if (dbhost)
{
keywords[i] = "host";
values[i] = dbhost;
i++;
}
if (dbuser)
{
keywords[i] = "user";
values[i] = dbuser;
i++;
}
if (dbport)
{
keywords[i] = "port";
values[i] = dbport;
i++;
}
/* If -W was given, force prompt for password, but only the first time */
need_password = (dbgetpassword == 1 && !have_password);
do
{
/* Get a new password if appropriate */
if (need_password)
{
simple_prompt("Password: ", password, sizeof(password), false);
have_password = true;
need_password = false;
}
/* Use (or reuse, on a subsequent connection) password if we have it */
if (have_password)
{
keywords[i] = "password";
values[i] = password;
}
else
{
keywords[i] = NULL;
values[i] = NULL;
}
tmpconn = PQconnectdbParams(keywords, values, true);
/*
* If there is too little memory even to allocate the PGconn object
* and PQconnectdbParams returns NULL, we call exit(1) directly.
*/
if (!tmpconn)
{
pg_log_error("could not connect to server");
exit(1);
}
/* If we need a password and -w wasn't given, loop back and get one */
if (PQstatus(tmpconn) == CONNECTION_BAD &&
PQconnectionNeedsPassword(tmpconn) &&
dbgetpassword != -1)
{
PQfinish(tmpconn);
need_password = true;
}
}
while (need_password);
if (PQstatus(tmpconn) != CONNECTION_OK)
{
pg_log_error("could not connect to server: %s",
PQerrorMessage(tmpconn));
PQfinish(tmpconn);
free(values);
free(keywords);
if (conn_opts)
PQconninfoFree(conn_opts);
return NULL;
}
/* Connection ok! */
free(values);
free(keywords);
if (conn_opts)
PQconninfoFree(conn_opts);
/*
* Set always-secure search path, so malicious users can't get control.
* The capacity to run normal SQL queries was added in PostgreSQL 10, so
* the search path cannot be changed (by us or attackers) on earlier
* versions.
*/
if (dbname != NULL && PQserverVersion(tmpconn) >= 100000)
{
PGresult *res;
res = PQexec(tmpconn, ALWAYS_SECURE_SEARCH_PATH_SQL);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
pg_log_error("could not clear search_path: %s",
PQerrorMessage(tmpconn));
PQclear(res);
PQfinish(tmpconn);
exit(1);
}
PQclear(res);
}
/*
* Ensure we have the same value of integer_datetimes (now always "on") as
* the server we are connecting to.
*/
tmpparam = PQparameterStatus(tmpconn, "integer_datetimes");
if (!tmpparam)
{
pg_log_error("could not determine server setting for integer_datetimes");
PQfinish(tmpconn);
exit(1);
}
if (strcmp(tmpparam, "on") != 0)
{
pg_log_error("integer_datetimes compile flag does not match server");
PQfinish(tmpconn);
exit(1);
}
/*
* Retrieve the source data directory mode and use it to construct a umask
* for creating directories and files.
*/
if (!RetrieveDataDirCreatePerm(tmpconn))
{
PQfinish(tmpconn);
exit(1);
}
return tmpconn;
}
/*
* From version 10, explicitly set wal segment size using SHOW wal_segment_size
* since ControlFile is not accessible here.
*/
bool
RetrieveWalSegSize(PGconn *conn)
{
PGresult *res;
char xlog_unit[3];
int xlog_val,
multiplier = 1;
/* check connection existence */
Assert(conn != NULL);
/* for previous versions set the default xlog seg size */
if (PQserverVersion(conn) < MINIMUM_VERSION_FOR_SHOW_CMD)
{
WalSegSz = DEFAULT_XLOG_SEG_SIZE;
return true;
}
res = PQexec(conn, "SHOW wal_segment_size");
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
pg_log_error("could not send replication command \"%s\": %s",
"SHOW wal_segment_size", PQerrorMessage(conn));
PQclear(res);
return false;
}
if (PQntuples(res) != 1 || PQnfields(res) < 1)
{
pg_log_error("could not fetch WAL segment size: got %d rows and %d fields, expected %d rows and %d or more fields",
PQntuples(res), PQnfields(res), 1, 1);
PQclear(res);
return false;
}
/* fetch xlog value and unit from the result */
if (sscanf(PQgetvalue(res, 0, 0), "%d%s", &xlog_val, xlog_unit) != 2)
{
pg_log_error("WAL segment size could not be parsed");
return false;
}
/* set the multiplier based on unit to convert xlog_val to bytes */
if (strcmp(xlog_unit, "MB") == 0)
multiplier = 1024 * 1024;
else if (strcmp(xlog_unit, "GB") == 0)
multiplier = 1024 * 1024 * 1024;
/* convert and set WalSegSz */
WalSegSz = xlog_val * multiplier;
if (!IsValidWalSegSize(WalSegSz))
{
pg_log_error(ngettext("WAL segment size must be a power of two between 1 MB and 1 GB, but the remote server reported a value of %d byte",
"WAL segment size must be a power of two between 1 MB and 1 GB, but the remote server reported a value of %d bytes",
WalSegSz),
WalSegSz);
return false;
}
PQclear(res);
return true;
}
/*
* RetrieveDataDirCreatePerm
*
* This function is used to determine the privileges on the server's PG data
* directory and, based on that, set what the permissions will be for
* directories and files we create.
*
* PG11 added support for (optionally) group read/execute rights to be set on
* the data directory. Prior to PG11, only the owner was allowed to have rights
* on the data directory.
*/
static bool
RetrieveDataDirCreatePerm(PGconn *conn)
{
PGresult *res;
int data_directory_mode;
/* check connection existence */
Assert(conn != NULL);
/* for previous versions leave the default group access */
if (PQserverVersion(conn) < MINIMUM_VERSION_FOR_GROUP_ACCESS)
return true;
res = PQexec(conn, "SHOW data_directory_mode");
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
pg_log_error("could not send replication command \"%s\": %s",
"SHOW data_directory_mode", PQerrorMessage(conn));
PQclear(res);
return false;
}
if (PQntuples(res) != 1 || PQnfields(res) < 1)
{
pg_log_error("could not fetch group access flag: got %d rows and %d fields, expected %d rows and %d or more fields",
PQntuples(res), PQnfields(res), 1, 1);
PQclear(res);
return false;
}
if (sscanf(PQgetvalue(res, 0, 0), "%o", &data_directory_mode) != 1)
{
pg_log_error("group access flag could not be parsed: %s",
PQgetvalue(res, 0, 0));
PQclear(res);
return false;
}
SetDataDirectoryCreatePerm(data_directory_mode);
PQclear(res);
return true;
}
/*
* Run IDENTIFY_SYSTEM through a given connection and give back to caller
* some result information if requested:
* - System identifier
* - Current timeline ID
* - Start LSN position
* - Database name (NULL in servers prior to 9.4)
*/
bool
RunIdentifySystem(PGconn *conn, char **sysid, TimeLineID *starttli,
XLogRecPtr *startpos, char **db_name)
{
PGresult *res;
uint32 hi,
lo;
/* Check connection existence */
Assert(conn != NULL);
res = PQexec(conn, "IDENTIFY_SYSTEM");
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
pg_log_error("could not send replication command \"%s\": %s",
"IDENTIFY_SYSTEM", PQerrorMessage(conn));
PQclear(res);
return false;
}
if (PQntuples(res) != 1 || PQnfields(res) < 3)
{
pg_log_error("could not identify system: got %d rows and %d fields, expected %d rows and %d or more fields",
PQntuples(res), PQnfields(res), 1, 3);
PQclear(res);
return false;
}
/* Get system identifier */
if (sysid != NULL)
*sysid = pg_strdup(PQgetvalue(res, 0, 0));
/* Get timeline ID to start streaming from */
if (starttli != NULL)
*starttli = atoi(PQgetvalue(res, 0, 1));
/* Get LSN start position if necessary */
if (startpos != NULL)
{
if (sscanf(PQgetvalue(res, 0, 2), "%X/%X", &hi, &lo) != 2)
{
pg_log_error("could not parse write-ahead log location \"%s\"",
PQgetvalue(res, 0, 2));
PQclear(res);
return false;
}
*startpos = ((uint64) hi) << 32 | lo;
}
/* Get database name, only available in 9.4 and newer versions */
if (db_name != NULL)
{
*db_name = NULL;
if (PQserverVersion(conn) >= 90400)
{
if (PQnfields(res) < 4)
{
pg_log_error("could not identify system: got %d rows and %d fields, expected %d rows and %d or more fields",
PQntuples(res), PQnfields(res), 1, 4);
PQclear(res);
return false;
}
if (!PQgetisnull(res, 0, 3))
*db_name = pg_strdup(PQgetvalue(res, 0, 3));
}
}
PQclear(res);
return true;
}
/*
* Create a replication slot for the given connection. This function
* returns true in case of success.
*/
bool
CreateReplicationSlot(PGconn *conn, const char *slot_name, const char *plugin,
bool is_temporary, bool is_physical, bool reserve_wal,
bool slot_exists_ok)
{
PQExpBuffer query;
PGresult *res;
query = createPQExpBuffer();
Assert((is_physical && plugin == NULL) ||
(!is_physical && plugin != NULL));
Assert(slot_name != NULL);
/* Build query */
appendPQExpBuffer(query, "CREATE_REPLICATION_SLOT \"%s\"", slot_name);
if (is_temporary)
appendPQExpBuffer(query, " TEMPORARY");
if (is_physical)
{
appendPQExpBuffer(query, " PHYSICAL");
if (reserve_wal)
appendPQExpBuffer(query, " RESERVE_WAL");
}
else
{
appendPQExpBuffer(query, " LOGICAL \"%s\"", plugin);
if (PQserverVersion(conn) >= 100000)
/* pg_recvlogical doesn't use an exported snapshot, so suppress */
appendPQExpBuffer(query, " NOEXPORT_SNAPSHOT");
}
res = PQexec(conn, query->data);
if (PQresultStatus(res) != PGRES_TUPLES_OK)
{
const char *sqlstate = PQresultErrorField(res, PG_DIAG_SQLSTATE);
if (slot_exists_ok &&
sqlstate &&
strcmp(sqlstate, ERRCODE_DUPLICATE_OBJECT) == 0)
{
destroyPQExpBuffer(query);
PQclear(res);
return true;
}
else
{
pg_log_error("could not send replication command \"%s\": %s",
query->data, PQerrorMessage(conn));
destroyPQExpBuffer(query);
PQclear(res);
return false;
}
}
if (PQntuples(res) != 1 || PQnfields(res) != 4)
{
pg_log_error("could not create replication slot \"%s\": got %d rows and %d fields, expected %d rows and %d fields",
slot_name,
PQntuples(res), PQnfields(res), 1, 4);
destroyPQExpBuffer(query);
PQclear(res);
return false;
}
destroyPQExpBuffer(query);
PQclear(res);
return true;
}
/*
* Drop a replication slot for the given connection. This function
* returns true in case of success.
*/
bool
DropReplicationSlot(PGconn *conn, const char *slot_name)
{
PQExpBuffer query;
PGresult *res;
Assert(slot_name != NULL);
query = createPQExpBuffer();
/* Build query */
appendPQExpBuffer(query, "DROP_REPLICATION_SLOT \"%s\"",
slot_name);
res = PQexec(conn, query->data);
if (PQresultStatus(res) != PGRES_COMMAND_OK)
{
pg_log_error("could not send replication command \"%s\": %s",
query->data, PQerrorMessage(conn));
destroyPQExpBuffer(query);
PQclear(res);
return false;
}
if (PQntuples(res) != 0 || PQnfields(res) != 0)
{
pg_log_error("could not drop replication slot \"%s\": got %d rows and %d fields, expected %d rows and %d fields",
slot_name,
PQntuples(res), PQnfields(res), 0, 0);
destroyPQExpBuffer(query);
PQclear(res);
return false;
}
destroyPQExpBuffer(query);
PQclear(res);
return true;
}
/*
* Frontend version of GetCurrentTimestamp(), since we are not linked with
* backend code.
*/
TimestampTz
feGetCurrentTimestamp(void)
{
TimestampTz result;
struct timeval tp;
gettimeofday(&tp, NULL);
result = (TimestampTz) tp.tv_sec -
((POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY);
result = (result * USECS_PER_SEC) + tp.tv_usec;
return result;
}
/*
* Frontend version of TimestampDifference(), since we are not linked with
* backend code.
*/
void
feTimestampDifference(TimestampTz start_time, TimestampTz stop_time,
long *secs, int *microsecs)
{
TimestampTz diff = stop_time - start_time;
if (diff <= 0)
{
*secs = 0;
*microsecs = 0;
}
else
{
*secs = (long) (diff / USECS_PER_SEC);
*microsecs = (int) (diff % USECS_PER_SEC);
}
}
/*
* Frontend version of TimestampDifferenceExceeds(), since we are not
* linked with backend code.
*/
bool
feTimestampDifferenceExceeds(TimestampTz start_time,
TimestampTz stop_time,
int msec)
{
TimestampTz diff = stop_time - start_time;
return (diff >= msec * INT64CONST(1000));
}
/*
* Converts an int64 to network byte order.
*/
void
fe_sendint64(int64 i, char *buf)
{
uint64 n64 = pg_hton64(i);
memcpy(buf, &n64, sizeof(n64));
}
/*
* Converts an int64 from network byte order to native format.
*/
int64
fe_recvint64(char *buf)
{
uint64 n64;
memcpy(&n64, buf, sizeof(n64));
return pg_ntoh64(n64);
}
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