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/*-------------------------------------------------------------------------
*
* cmdtag.c
* Data and routines for commandtag names and enumeration.
*
* Portions Copyright (c) 1996-2023, PostgreSQL Global Development Group
* Portions Copyright (c) 1994, Regents of the University of California
*
* IDENTIFICATION
* src/backend/tcop/cmdtag.c
*
*-------------------------------------------------------------------------
*/
#include "postgres.h"
#include "miscadmin.h"
#include "tcop/cmdtag.h"
#include "utils/builtins.h"
typedef struct CommandTagBehavior
{
const char *name; /* tag name, e.g. "SELECT" */
const uint8 namelen; /* set to strlen(name) */
const bool event_trigger_ok;
const bool table_rewrite_ok;
const bool display_rowcount; /* should the number of rows affected be
* shown in the command completion string */
} CommandTagBehavior;
#define PG_CMDTAG(tag, name, evtrgok, rwrok, rowcnt) \
{ name, (uint8) (sizeof(name) - 1), evtrgok, rwrok, rowcnt },
static const CommandTagBehavior tag_behavior[COMMAND_TAG_NEXTTAG] = {
#include "tcop/cmdtaglist.h"
};
#undef PG_CMDTAG
void
InitializeQueryCompletion(QueryCompletion *qc)
{
qc->commandTag = CMDTAG_UNKNOWN;
qc->nprocessed = 0;
}
const char *
GetCommandTagName(CommandTag commandTag)
{
return tag_behavior[commandTag].name;
}
const char *
GetCommandTagNameAndLen(CommandTag commandTag, Size *len)
{
*len = (Size) tag_behavior[commandTag].namelen;
return tag_behavior[commandTag].name;
}
bool
command_tag_display_rowcount(CommandTag commandTag)
{
return tag_behavior[commandTag].display_rowcount;
}
bool
command_tag_event_trigger_ok(CommandTag commandTag)
{
return tag_behavior[commandTag].event_trigger_ok;
}
bool
command_tag_table_rewrite_ok(CommandTag commandTag)
{
return tag_behavior[commandTag].table_rewrite_ok;
}
/*
* Search CommandTag by name
*
* Returns CommandTag, or CMDTAG_UNKNOWN if not recognized
*/
CommandTag
GetCommandTagEnum(const char *commandname)
{
const CommandTagBehavior *base,
*last,
*position;
int result;
if (commandname == NULL || *commandname == '\0')
return CMDTAG_UNKNOWN;
base = tag_behavior;
last = tag_behavior + lengthof(tag_behavior) - 1;
while (last >= base)
{
position = base + ((last - base) >> 1);
result = pg_strcasecmp(commandname, position->name);
if (result == 0)
return (CommandTag) (position - tag_behavior);
else if (result < 0)
last = position - 1;
else
base = position + 1;
}
return CMDTAG_UNKNOWN;
}
/*
* BuildQueryCompletionString
* Build a string containing the command tag name with the
* QueryCompletion's nprocessed for command tags with display_rowcount
* set. Returns the strlen of the constructed string.
*
* The caller must ensure that buff is at least COMPLETION_TAG_BUFSIZE bytes.
*
* If nameonly is true, then the constructed string will contain only the tag
* name.
*/
Size
BuildQueryCompletionString(char *buff, const QueryCompletion *qc,
bool nameonly)
{
CommandTag tag = qc->commandTag;
Size taglen;
const char *tagname = GetCommandTagNameAndLen(tag, &taglen);
char *bufp;
/*
* We assume the tagname is plain ASCII and therefore requires no encoding
* conversion.
*/
memcpy(buff, tagname, taglen);
bufp = buff + taglen;
/* ensure that the tagname isn't long enough to overrun the buffer */
Assert(taglen <= COMPLETION_TAG_BUFSIZE - MAXINT8LEN - 4);
/*
* In PostgreSQL versions 11 and earlier, it was possible to create a
* table WITH OIDS. When inserting into such a table, INSERT used to
* include the Oid of the inserted record in the completion tag. To
* maintain compatibility in the wire protocol, we now write a "0" (for
* InvalidOid) in the location where we once wrote the new record's Oid.
*/
if (command_tag_display_rowcount(tag) && !nameonly)
{
if (tag == CMDTAG_INSERT)
{
*bufp++ = ' ';
*bufp++ = '0';
}
*bufp++ = ' ';
bufp += pg_ulltoa_n(qc->nprocessed, bufp);
}
/* and finally, NUL terminate the string */
*bufp = '\0';
Assert((bufp - buff) == strlen(buff));
return bufp - buff;
}
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