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Update libpq to make new features of FE/BE protocol available to

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client applications.  Some editorial work on libpq.sgml, too.
This commit is contained in:
Tom Lane
2003-06-21 21:51:35 +00:00
parent b8d601e735
commit efc3a25bb0
11 changed files with 2523 additions and 831 deletions
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194
src/interfaces/libpq/fe-protocol2.c
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@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-protocol2.c,v 1.1 2003/06/08 17:43:00 tgl Exp $
* $Header: /cvsroot/pgsql/src/interfaces/libpq/fe-protocol2.c,v 1.2 2003/06/21 21:51:34 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -38,6 +38,7 @@
static int getRowDescriptions(PGconn *conn);
static int getAnotherTuple(PGconn *conn, bool binary);
static int pqGetErrorNotice2(PGconn *conn, bool isError);
static void checkXactStatus(PGconn *conn, const char *cmdTag);
static int getNotify(PGconn *conn);
@ -312,7 +313,7 @@ pqSetenvPoll(PGconn *conn)
val);
else
{
val = pqGetParameterStatus(conn, "server_encoding");
val = PQparameterStatus(conn, "server_encoding");
if (val && *val)
pqSaveParameterStatus(conn, "client_encoding",
val);
@ -424,7 +425,7 @@ pqParseInput2(PGconn *conn)
else
{
snprintf(noticeWorkspace, sizeof(noticeWorkspace),
libpq_gettext("message type 0x%02x arrived from server while idle\n"),
libpq_gettext("message type 0x%02x arrived from server while idle"),
id);
PGDONOTICE(conn, noticeWorkspace);
/* Discard the unexpected message; good idea?? */
@ -447,6 +448,7 @@ pqParseInput2(PGconn *conn)
PGRES_COMMAND_OK);
strncpy(conn->result->cmdStatus, conn->workBuffer.data,
CMDSTATUS_LEN);
checkXactStatus(conn, conn->workBuffer.data);
conn->asyncStatus = PGASYNC_READY;
break;
case 'E': /* error return */
@ -464,7 +466,7 @@ pqParseInput2(PGconn *conn)
if (id != '\0')
{
snprintf(noticeWorkspace, sizeof(noticeWorkspace),
libpq_gettext("unexpected character %c following empty query response (\"I\" message)\n"),
libpq_gettext("unexpected character %c following empty query response (\"I\" message)"),
id);
PGDONOTICE(conn, noticeWorkspace);
}
@ -521,7 +523,7 @@ pqParseInput2(PGconn *conn)
else
{
snprintf(noticeWorkspace, sizeof(noticeWorkspace),
libpq_gettext("server sent data (\"D\" message) without prior row description (\"T\" message)\n"));
libpq_gettext("server sent data (\"D\" message) without prior row description (\"T\" message)"));
PGDONOTICE(conn, noticeWorkspace);
/* Discard the unexpected message; good idea?? */
conn->inStart = conn->inEnd;
@ -538,7 +540,7 @@ pqParseInput2(PGconn *conn)
else
{
snprintf(noticeWorkspace, sizeof(noticeWorkspace),
libpq_gettext("server sent binary data (\"B\" message) without prior row description (\"T\" message)\n"));
libpq_gettext("server sent binary data (\"B\" message) without prior row description (\"T\" message)"));
PGDONOTICE(conn, noticeWorkspace);
/* Discard the unexpected message; good idea?? */
conn->inStart = conn->inEnd;
@ -628,6 +630,9 @@ getRowDescriptions(PGconn *conn)
result->attDescs[i].name = pqResultStrdup(result,
conn->workBuffer.data);
result->attDescs[i].tableid = 0;
result->attDescs[i].columnid = 0;
result->attDescs[i].format = 0;
result->attDescs[i].typid = typid;
result->attDescs[i].typlen = typlen;
result->attDescs[i].atttypmod = atttypmod;
@ -674,6 +679,15 @@ getAnotherTuple(PGconn *conn, bool binary)
if (conn->curTuple == NULL)
goto outOfMemory;
MemSet((char *) conn->curTuple, 0, nfields * sizeof(PGresAttValue));
/*
* If it's binary, fix the column format indicators. We assume
* the backend will consistently send either B or D, not a mix.
*/
if (binary)
{
for (i = 0; i < nfields; i++)
result->attDescs[i].format = 1;
}
}
tup = conn->curTuple;
@ -778,6 +792,8 @@ pqGetErrorNotice2(PGconn *conn, bool isError)
{
PGresult *res;
PQExpBufferData workBuf;
char *startp;
char *splitp;
/*
* Since the message might be pretty long, we create a temporary
@ -800,19 +816,63 @@ pqGetErrorNotice2(PGconn *conn, bool isError)
res->resultStatus = isError ? PGRES_FATAL_ERROR : PGRES_NONFATAL_ERROR;
res->errMsg = pqResultStrdup(res, workBuf.data);
/*
* Break the message into fields. We can't do very much here, but we
* can split the severity code off, and remove trailing newlines. Also,
* we use the heuristic that the primary message extends only to the
* first newline --- anything after that is detail message. (In some
* cases it'd be better classed as hint, but we can hardly be expected
* to guess that here.)
*/
while (workBuf.len > 0 && workBuf.data[workBuf.len-1] == '\n')
workBuf.data[--workBuf.len] = '\0';
splitp = strstr(workBuf.data, ": ");
if (splitp)
{
/* what comes before the colon is severity */
*splitp = '\0';
pqSaveMessageField(res, 'S', workBuf.data);
startp = splitp + 3;
}
else
{
/* can't find a colon? oh well... */
startp = workBuf.data;
}
splitp = strchr(startp, '\n');
if (splitp)
{
/* what comes before the newline is primary message */
*splitp++ = '\0';
pqSaveMessageField(res, 'M', startp);
/* the rest is detail; strip any leading whitespace */
while (*splitp && isspace((unsigned char) *splitp))
splitp++;
pqSaveMessageField(res, 'D', splitp);
}
else
{
/* single-line message, so all primary */
pqSaveMessageField(res, 'M', startp);
}
/*
* Either save error as current async result, or just emit the notice.
* Also, if it's an error and we were in a transaction block, assume
* the server has now gone to error-in-transaction state.
*/
if (isError)
{
pqClearAsyncResult(conn);
conn->result = res;
resetPQExpBuffer(&conn->errorMessage);
appendPQExpBufferStr(&conn->errorMessage, workBuf.data);
appendPQExpBufferStr(&conn->errorMessage, res->errMsg);
if (conn->xactStatus == PQTRANS_INTRANS)
conn->xactStatus = PQTRANS_INERROR;
}
else
{
PGDONOTICE(conn, workBuf.data);
(*res->noticeHooks.noticeRec) (res->noticeHooks.noticeRecArg, res);
PQclear(res);
}
@ -820,6 +880,37 @@ pqGetErrorNotice2(PGconn *conn, bool isError)
return 0;
}
/*
* checkXactStatus - attempt to track transaction-block status of server
*
* This is called each time we receive a command-complete message. By
* watching for messages from BEGIN/COMMIT/ROLLBACK commands, we can do
* a passable job of tracking the server's xact status. BUT: this does
* not work at all on 7.3 servers with AUTOCOMMIT OFF. (Man, was that
* feature ever a mistake.) Caveat user.
*
* The tags known here are all those used as far back as 7.0; is it worth
* adding those from even-older servers?
*/
static void
checkXactStatus(PGconn *conn, const char *cmdTag)
{
if (strcmp(cmdTag, "BEGIN") == 0)
conn->xactStatus = PQTRANS_INTRANS;
else if (strcmp(cmdTag, "COMMIT") == 0)
conn->xactStatus = PQTRANS_IDLE;
else if (strcmp(cmdTag, "ROLLBACK") == 0)
conn->xactStatus = PQTRANS_IDLE;
else if (strcmp(cmdTag, "START TRANSACTION") == 0) /* 7.3 only */
conn->xactStatus = PQTRANS_INTRANS;
/*
* Normally we get into INERROR state by detecting an Error message.
* However, if we see one of these tags then we know for sure the
* server is in abort state ...
*/
else if (strcmp(cmdTag, "*ABORT STATE*") == 0) /* pre-7.3 only */
conn->xactStatus = PQTRANS_INERROR;
}
/*
* Attempt to read a Notify response message.
@ -832,6 +923,7 @@ static int
getNotify(PGconn *conn)
{
int be_pid;
int nmlen;
PGnotify *newNotify;
if (pqGetInt(&be_pid, 4, conn))
@ -844,12 +936,14 @@ getNotify(PGconn *conn)
* can all be freed at once. We don't use NAMEDATALEN because we
* don't want to tie this interface to a specific server name length.
*/
newNotify = (PGnotify *) malloc(sizeof(PGnotify) +
strlen(conn->workBuffer.data) +1);
nmlen = strlen(conn->workBuffer.data);
newNotify = (PGnotify *) malloc(sizeof(PGnotify) + nmlen + 1);
if (newNotify)
{
newNotify->relname = (char *) newNotify + sizeof(PGnotify);
strcpy(newNotify->relname, conn->workBuffer.data);
/* fake up an empty-string extra field */
newNotify->extra = newNotify->relname + nmlen;
newNotify->be_pid = be_pid;
DLAddTail(conn->notifyList, DLNewElem(newNotify));
}
@ -858,6 +952,84 @@ getNotify(PGconn *conn)
}
/*
* PQgetCopyData - read a row of data from the backend during COPY OUT
*
* If successful, sets *buffer to point to a malloc'd row of data, and
* returns row length (always > 0) as result.
* Returns 0 if no row available yet (only possible if async is true),
* -1 if end of copy (consult PQgetResult), or -2 if error (consult
* PQerrorMessage).
*/
int
pqGetCopyData2(PGconn *conn, char **buffer, int async)
{
bool found;
int msgLength;
for (;;)
{
/*
* Do we have a complete line of data?
*/
conn->inCursor = conn->inStart;
found = false;
while (conn->inCursor < conn->inEnd)
{
char c = conn->inBuffer[conn->inCursor++];
if (c == '\n')
{
found = true;
break;
}
}
if (!found)
goto nodata;
msgLength = conn->inCursor - conn->inStart;
/*
* If it's the end-of-data marker, consume it, exit COPY_OUT mode,
* and let caller read status with PQgetResult().
*/
if (msgLength == 3 &&
strncmp(&conn->inBuffer[conn->inStart], "\\.\n", 3) == 0)
{
conn->inStart = conn->inCursor;
conn->asyncStatus = PGASYNC_BUSY;
return -1;
}
/*
* Pass the line back to the caller.
*/
*buffer = (char *) malloc(msgLength + 1);
if (*buffer == NULL)
{
printfPQExpBuffer(&conn->errorMessage,
libpq_gettext("out of memory\n"));
return -2;
}
memcpy(*buffer, &conn->inBuffer[conn->inStart], msgLength);
(*buffer)[msgLength] = '\0'; /* Add terminating null */
/* Mark message consumed */
conn->inStart = conn->inCursor;
return msgLength;
nodata:
/* Don't block if async read requested */
if (async)
return 0;
/* Need to load more data */
if (pqWait(TRUE, FALSE, conn) ||
pqReadData(conn) < 0)
return -2;
}
}
/*
* PQgetline - gets a newline-terminated string from the backend.
*
@ -1020,7 +1192,7 @@ pqEndcopy2(PGconn *conn)
if (conn->errorMessage.len > 0)
PGDONOTICE(conn, conn->errorMessage.data);
PGDONOTICE(conn, libpq_gettext("lost synchronization with server, resetting connection\n"));
PGDONOTICE(conn, libpq_gettext("lost synchronization with server, resetting connection"));
/*
* Users doing non-blocking connections need to handle the reset