Re: Some new SPI functions - Mailing list pgsql-patches

Patch applied.  Thanks.

---------------------------------------------------------------------------


Thomas Hallgren wrote:
> > Who did you think would do it?
> >
> > regards, tom lane
> >
> you :-)
>
> Seriously, I didn't give it much though. This is undoubtedly the best way
> although some projects handle it differently. A  tech-writer perhaps, with
> better writing skills then programmers in general. But people like that are
> probabaly not too common in the open source field. If you don't do like
> JBoss and charge for the docs (I'm *not* in favor of that).
>
> Anyway, here's the patch again. This time with documentation.
>
> Index: doc/src/sgml/spi.sgml
> ===================================================================
> retrieving revision 1.30
> diff -u -r1.30 spi.sgml
> --- doc/src/sgml/spi.sgml 1 Dec 2003 22:07:57 -0000 1.30
> +++ doc/src/sgml/spi.sgml 15 Feb 2004 13:47:13 -0000
> @@ -573,6 +573,190 @@
>
>  <!-- *********************************************** -->
>
> +<refentry id="spi-spi-getargcount">
> + <refmeta>
> +  <refentrytitle>SPI_getargcount</refentrytitle>
> + </refmeta>
> +
> + <refnamediv>
> +  <refname>SPI_getargcount</refname>
> +  <refpurpose>returns the number of arguments needed when executing a plan
> +  prepared by <function>SPI_prepare</function></refpurpose>
> + </refnamediv>
> +
> + <indexterm><primary>SPI_getargcount</primary></indexterm>
> +
> + <refsynopsisdiv>
> +<synopsis>
> +int SPI_getargcount(void * <parameter>plan</parameter>)
> +</synopsis>
> + </refsynopsisdiv>
> +
> + <refsect1>
> +  <title>Description</title>
> +
> +  <para>
> +   <function>SPI_getargcount</function> returns the number of arguments
> needed
> +   when executing a plan prepared by <function>SPI_prepare</function>.
> +  </para>
> + </refsect1>
> +
> + <refsect1>
> +  <title>Arguments</title>
> +
> +  <variablelist>
> +   <varlistentry>
> +    <term><literal>void * <parameter>plan</parameter></literal></term>
> +    <listitem>
> +     <para>
> +      execution plan (returned by <function>SPI_prepare</function>)
> +     </para>
> +    </listitem>
> +   </varlistentry>
> +  </variablelist>
> + </refsect1>
> +
> + <refsect1>
> +  <title>Return Value</title>
> +  <para>
> +    The expected argument count for the <parameter>plan</parameter> or
> +    <symbol>SPI_ERROR_ARGUMENT</symbol> if the <parameter>plan
> +    </parameter> is <symbol>NULL</symbol>
> +  </para>
> + </refsect1>
> +</refentry>
> +
> +<!-- *********************************************** -->
> +
> +<refentry id="spi-spi-getargtypeid">
> + <refmeta>
> +  <refentrytitle>SPI_getargtypeid</refentrytitle>
> + </refmeta>
> +
> + <refnamediv>
> +  <refname>SPI_getargtypeid</refname>
> +  <refpurpose>returns the expected typeid for the specified argument when
> +  executing a plan prepared by
> <function>SPI_prepare</function></refpurpose>
> + </refnamediv>
> +
> + <indexterm><primary>SPI_getargtypeid</primary></indexterm>
> +
> + <refsynopsisdiv>
> +<synopsis>
> +Oid SPI_getargtypeid(void * <parameter>plan</parameter>, int
> <parameter>argIndex</parameter>)
> +</synopsis>
> + </refsynopsisdiv>
> +
> + <refsect1>
> +  <title>Description</title>
> +
> +  <para>
> +   <function>SPI_getargtypeid</function> returns the Oid representing the
> type
> +   id for argument at <parameter>argIndex</parameter> in a plan prepared by
> +   <function>SPI_prepare</function>. First argument is at index zero.
> +  </para>
> + </refsect1>
> +
> + <refsect1>
> +  <title>Arguments</title>
> +
> +  <variablelist>
> +   <varlistentry>
> +    <term><literal>void * <parameter>plan</parameter></literal></term>
> +    <listitem>
> +     <para>
> +      execution plan (returned by <function>SPI_prepare</function>)
> +     </para>
> +    </listitem>
> +   </varlistentry>
> +
> +   <varlistentry>
> +    <term><literal>int <parameter>argIndex</parameter></literal></term>
> +    <listitem>
> +     <para>
> +      zero based index of the argument
> +     </para>
> +    </listitem>
> +   </varlistentry>
> +  </variablelist>
> + </refsect1>
> +
> + <refsect1>
> +  <title>Return Value</title>
> +  <para>
> +    The type id of the argument at the given index or <symbol>
> +    SPI_ERROR_ARGUMENT</symbol> if the <parameter>plan</parameter> is
> +    <symbol>NULL</symbol> or <parameter>argIndex</parameter> is less than 0
> or
> +    not less than the number of arguments declared for the <parameter>plan
> +    </parameter>
> +  </para>
> + </refsect1>
> +</refentry>
> +
> +<!-- *********************************************** -->
> +
> +<refentry id="spi-spi-is_cursor_plan">
> + <refmeta>
> +  <refentrytitle>SPI_is_cursor_plan</refentrytitle>
> + </refmeta>
> +
> + <refnamediv>
> +  <refname>SPI_is_cursor_plan</refname>
> +  <refpurpose>returns <symbol>true</symbol> if a plan
> +  prepared by <function>SPI_prepare</function> can be passed
> +  as an argument to <function>SPI_cursor_open</function></refpurpose>
> + </refnamediv>
> +
> + <indexterm><primary>SPI_is_cursor_plan</primary></indexterm>
> +
> + <refsynopsisdiv>
> +<synopsis>
> +bool SPI_is_cursor_plan(void * <parameter>plan</parameter>)
> +</synopsis>
> + </refsynopsisdiv>
> +
> + <refsect1>
> +  <title>Description</title>
> +
> +  <para>
> +   <function>SPI_is_cursor_plan</function> returns <symbol>true</symbol>
> +   if a plan prepared by <function>SPI_prepare</function> can be passed
> +   as an argument to <function>SPI_cursor_open</function> and <symbol>
> +   false</symbol> if that is not the case. The criteria is that the
> +   <parameter>plan</parameter> represents one single command and that this
> +   command is a <command>SELECT</command> without an
> <command>INTO</command>
> +   clause.
> +  </para>
> + </refsect1>
> +
> + <refsect1>
> +  <title>Arguments</title>
> +
> +  <variablelist>
> +   <varlistentry>
> +    <term><literal>void * <parameter>plan</parameter></literal></term>
> +    <listitem>
> +     <para>
> +      execution plan (returned by <function>SPI_prepare</function>)
> +     </para>
> +    </listitem>
> +   </varlistentry>
> +  </variablelist>
> + </refsect1>
> +
> + <refsect1>
> +  <title>Return Value</title>
> +  <para>
> +    <symbol>true</symbol> or <symbol>false</symbol> to indicate if the
> +    <parameter>plan</parameter> can produce a cursor or not, or
> +    <symbol>SPI_ERROR_ARGUMENT</symbol> if the <parameter>plan</parameter>
> +    is <symbol>NULL</symbol>
> +  </para>
> + </refsect1>
> +</refentry>
> +
> +<!-- *********************************************** -->
> +
>  <refentry id="spi-spi-execp">
>   <refmeta>
>    <refentrytitle>SPI_execp</refentrytitle>
> Index: src/backend/executor/spi.c
> ===================================================================
> retrieving revision 1.109
> diff -u -r1.109 spi.c
> --- src/backend/executor/spi.c 2 Dec 2003 19:26:47 -0000 1.109
> +++ src/backend/executor/spi.c 15 Feb 2004 13:47:18 -0000
> @@ -918,6 +918,65 @@
>   PortalDrop(portal, false);
>  }
>
> +/*
> + * Returns the Oid representing the type id for argument at argIndex. First
> + * parameter is at index zero.
> + */
> +Oid
> +SPI_getargtypeid(void *plan, int argIndex)
> +{
> + if (plan == NULL || argIndex < 0 || argIndex >= ((_SPI_plan*)plan)->nargs)
> + {
> +  SPI_result = SPI_ERROR_ARGUMENT;
> +  return InvalidOid;
> + }
> + return ((_SPI_plan *) plan)->argtypes[argIndex];
> +}
> +
> +/*
> + * Returns the number of arguments for the prepared plan.
> + */
> +int
> +SPI_getargcount(void *plan)
> +{
> + if (plan == NULL)
> + {
> +  SPI_result = SPI_ERROR_ARGUMENT;
> +  return -1;
> + }
> + return ((_SPI_plan *) plan)->nargs;
> +}
> +
> +/*
> + * Returns true if the plan contains exactly one command
> + * and that command originates from normal SELECT (i.e.
> + * *not* a SELECT ... INTO). In essence, the result indicates
> + * if the command can be used with SPI_cursor_open
> + *
> + * Parameters
> + *    plan A plan previously prepared using SPI_prepare
> + */
> +bool
> +SPI_is_cursor_plan(void *plan)
> +{
> + List *qtlist;
> + _SPI_plan *spiplan = (_SPI_plan *) plan;
> + if (spiplan == NULL)
> + {
> +  SPI_result = SPI_ERROR_ARGUMENT;
> +  return false;
> + }
> +
> + qtlist = spiplan->qtlist;
> + if(length(spiplan->ptlist) == 1 && length(qtlist) == 1)
> + {
> +  Query *queryTree = (Query *) lfirst((List *) lfirst(qtlist));
> +  if(queryTree->commandType == CMD_SELECT && queryTree->into == NULL)
> +   return true;
> + }
> + return false;
> +}
> +
>  /* =================== private functions =================== */
>
>  /*
> Index: src/include/executor/spi.h
> ===================================================================
> retrieving revision 1.41
> diff -u -r1.41 spi.h
> --- src/include/executor/spi.h 2 Dec 2003 19:26:47 -0000 1.41
> +++ src/include/executor/spi.h 15 Feb 2004 13:47:32 -0000
> @@ -90,6 +90,10 @@
>  extern void *SPI_saveplan(void *plan);
>  extern int SPI_freeplan(void *plan);
>
> +extern Oid SPI_getargtypeid(void *plan, int argIndex);
> +extern int SPI_getargcount(void *plan);
> +extern bool SPI_is_cursor_plan(void *plan);
> +
>  extern HeapTuple SPI_copytuple(HeapTuple tuple);
>  extern TupleDesc SPI_copytupledesc(TupleDesc tupdesc);
>  extern TupleTableSlot *SPI_copytupleintoslot(HeapTuple tuple,
>
>
> ---------------------------(end of broadcast)---------------------------
> TIP 7: don't forget to increase your free space map settings
>

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