Re: [HACKERS] Improvements in psql hooks for variables - Mailing list pgsql-hackers
| From | Tom Lane |
|---|---|
| Subject | Re: [HACKERS] Improvements in psql hooks for variables |
| Date | |
| Msg-id | 9831.1485896832@sss.pgh.pa.us Whole thread Raw |
| In response to | Re: [HACKERS] Improvements in psql hooks for variables (Tom Lane <tgl@sss.pgh.pa.us>) |
| Responses |
Re: [HACKERS] Improvements in psql hooks for variables
Re: [HACKERS] Improvements in psql hooks for variables Re: [HACKERS] Improvements in psql hooks for variables |
| List | pgsql-hackers |
I wrote:
> Attached is a draft patch for that. I chose to make a second hook rather
> than complicate the assign hook API, mainly because it allows more code
> sharing --- all the bool vars can share the same substitute hook, and
> so can the three-way vars as long as "on" and "off" are the appropriate
> substitutes.
> I only touched the behavior for bool vars here, but if people like this
> solution it could be fleshed out to apply to all the built-in variables.
Attached is a finished version that includes hooks for all the variables
for which they were clearly sensible. (FETCH_COUNT doesn't seem to really
need one, and I didn't do anything with HISTSIZE or IGNOREEOF either.
It might be worth bringing the latter two into the hooks paradigm, but
that seems like fit material for a separate patch.)
I updated the documentation as well. I think this is committable if
there are not objections.
regards, tom lane
diff --git a/doc/src/sgml/ref/psql-ref.sgml b/doc/src/sgml/ref/psql-ref.sgml
index 4e51e90..b9c8fcc 100644
*** a/doc/src/sgml/ref/psql-ref.sgml
--- b/doc/src/sgml/ref/psql-ref.sgml
*************** EOF
*** 455,462 ****
any, by an equal sign on the command line. To unset a variable,
leave off the equal sign. To set a variable with an empty value,
use the equal sign but leave off the value. These assignments are
! done during a very early stage of start-up, so variables reserved
! for internal purposes might get overwritten later.
</para>
</listitem>
</varlistentry>
--- 455,462 ----
any, by an equal sign on the command line. To unset a variable,
leave off the equal sign. To set a variable with an empty value,
use the equal sign but leave off the value. These assignments are
! done during command line processing, so variables that reflect
! connection state will get overwritten later.
</para>
</listitem>
</varlistentry>
*************** lo_import 152801
*** 2692,2698 ****
class="parameter">name</replaceable> to <replaceable
class="parameter">value</replaceable>, or if more than one value
is given, to the concatenation of all of them. If only one
! argument is given, the variable is set with an empty value. To
unset a variable, use the <command>\unset</command> command.
</para>
--- 2692,2698 ----
class="parameter">name</replaceable> to <replaceable
class="parameter">value</replaceable>, or if more than one value
is given, to the concatenation of all of them. If only one
! argument is given, the variable is set to an empty-string value. To
unset a variable, use the <command>\unset</command> command.
</para>
*************** lo_import 152801
*** 2709,2717 ****
</para>
<para>
! Although you are welcome to set any variable to anything you
! want, <application>psql</application> treats several variables
! as special. They are documented in the section about variables.
</para>
<note>
--- 2709,2719 ----
</para>
<para>
! Certain variables are special, in that they
! control <application>psql</application>'s behavior or are
! automatically set to reflect connection state. These variables are
! documented in <xref linkend="APP-PSQL-variables"
! endterm="APP-PSQL-variables-title">, below.
</para>
<note>
*************** testdb=> <userinput>\setenv LESS -imx
*** 2835,2840 ****
--- 2837,2850 ----
Unsets (deletes) the <application>psql</> variable <replaceable
class="parameter">name</replaceable>.
</para>
+
+ <para>
+ Most variables that control <application>psql</application>'s behavior
+ cannot be unset; instead, an <literal>\unset</> command is interpreted
+ as setting them to their default values.
+ See <xref linkend="APP-PSQL-variables"
+ endterm="APP-PSQL-variables-title">, below.
+ </para>
</listitem>
</varlistentry>
*************** bar
*** 3053,3059 ****
<para>
If you call <command>\set</command> without a second argument, the
! variable is set, with an empty string as value. To unset (i.e., delete)
a variable, use the command <command>\unset</command>. To show the
values of all variables, call <command>\set</command> without any argument.
</para>
--- 3063,3069 ----
<para>
If you call <command>\set</command> without a second argument, the
! variable is set to an empty-string value. To unset (i.e., delete)
a variable, use the command <command>\unset</command>. To show the
values of all variables, call <command>\set</command> without any argument.
</para>
*************** bar
*** 3082,3089 ****
By convention, all specially treated variables' names
consist of all upper-case ASCII letters (and possibly digits and
underscores). To ensure maximum compatibility in the future, avoid
! using such variable names for your own purposes. A list of all specially
! treated variables follows.
</para>
<variablelist>
--- 3092,3114 ----
By convention, all specially treated variables' names
consist of all upper-case ASCII letters (and possibly digits and
underscores). To ensure maximum compatibility in the future, avoid
! using such variable names for your own purposes.
! </para>
!
! <para>
! Variables that control <application>psql</application>'s behavior
! generally cannot be unset or set to invalid values. An <literal>\unset</>
! command is allowed but is interpreted as setting the variable to its
! default value. A <literal>\set</> command without a second argument is
! interpreted as setting the variable to <literal>on</>, for control
! variables that accept that value, and is rejected for others. Also,
! control variables that accept the values <literal>on</>
! and <literal>off</> will also accept other common spellings of Boolean
! values, such as <literal>true</> and <literal>false</>.
! </para>
!
! <para>
! The specially treated variables are:
</para>
<variablelist>
*************** bar
*** 3153,3159 ****
<para>
The name of the database you are currently connected to. This is
set every time you connect to a database (including program
! start-up), but can be unset.
</para>
</listitem>
</varlistentry>
--- 3178,3184 ----
<para>
The name of the database you are currently connected to. This is
set every time you connect to a database (including program
! start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3171,3178 ****
as it is sent to the server. The switch to select this behavior is
<option>-e</option>. If set to <literal>errors</literal>, then only
failed queries are displayed on standard error output. The switch
! for this behavior is <option>-b</option>. If unset, or if set to
! <literal>none</literal>, then no queries are displayed.
</para>
</listitem>
</varlistentry>
--- 3196,3203 ----
as it is sent to the server. The switch to select this behavior is
<option>-e</option>. If set to <literal>errors</literal>, then only
failed queries are displayed on standard error output. The switch
! for this behavior is <option>-b</option>. If set to
! <literal>none</literal> (the default), then no queries are displayed.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3187,3194 ****
<productname>PostgreSQL</productname> internals and provide
similar functionality in your own programs. (To select this behavior
on program start-up, use the switch <option>-E</option>.) If you set
! the variable to the value <literal>noexec</literal>, the queries are
just shown but are not actually sent to the server and executed.
</para>
</listitem>
</varlistentry>
--- 3212,3220 ----
<productname>PostgreSQL</productname> internals and provide
similar functionality in your own programs. (To select this behavior
on program start-up, use the switch <option>-E</option>.) If you set
! this variable to the value <literal>noexec</literal>, the queries are
just shown but are not actually sent to the server and executed.
+ The default value is <literal>off</>.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3200,3206 ****
The current client character set encoding.
This is set every time you connect to a database (including
program start-up), and when you change the encoding
! with <literal>\encoding</>, but it can be unset.
</para>
</listitem>
</varlistentry>
--- 3226,3232 ----
The current client character set encoding.
This is set every time you connect to a database (including
program start-up), and when you change the encoding
! with <literal>\encoding</>, but it can be changed or unset.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3209,3215 ****
<term><varname>FETCH_COUNT</varname></term>
<listitem>
<para>
! If this variable is set to an integer value > 0,
the results of <command>SELECT</command> queries are fetched
and displayed in groups of that many rows, rather than the
default behavior of collecting the entire result set before
--- 3235,3241 ----
<term><varname>FETCH_COUNT</varname></term>
<listitem>
<para>
! If this variable is set to an integer value greater than zero,
the results of <command>SELECT</command> queries are fetched
and displayed in groups of that many rows, rather than the
default behavior of collecting the entire result set before
*************** bar
*** 3220,3225 ****
--- 3246,3258 ----
Keep in mind that when using this feature, a query might
fail after having already displayed some rows.
</para>
+
+ <para>
+ <varname>FETCH_COUNT</varname> is ignored if it is unset or does not
+ have a positive value. It cannot be set to a value that is not
+ syntactically an integer.
+ </para>
+
<tip>
<para>
Although you can use any output format with this feature,
*************** bar
*** 3241,3247 ****
list. If set to a value of <literal>ignoredups</literal>, lines
matching the previous history line are not entered. A value of
<literal>ignoreboth</literal> combines the two options. If
! unset, or if set to <literal>none</literal> (the default), all lines
read in interactive mode are saved on the history list.
</para>
<note>
--- 3274,3280 ----
list. If set to a value of <literal>ignoredups</literal>, lines
matching the previous history line are not entered. A value of
<literal>ignoreboth</literal> combines the two options. If
! set to <literal>none</literal> (the default), all lines
read in interactive mode are saved on the history list.
</para>
<note>
*************** bar
*** 3257,3264 ****
<term><varname>HISTFILE</varname></term>
<listitem>
<para>
! The file name that will be used to store the history list. The default
! value is <filename>~/.psql_history</filename>. For example, putting:
<programlisting>
\set HISTFILE ~/.psql_history- :DBNAME
</programlisting>
--- 3290,3301 ----
<term><varname>HISTFILE</varname></term>
<listitem>
<para>
! The file name that will be used to store the history list. If unset,
! the file name is taken from the <envar>PSQL_HISTORY</envar>
! environment variable. If that is not set either, the default
! is <filename>~/.psql_history</filename>,
! or <filename>%APPDATA%\postgresql\psql_history</filename> on Windows.
! For example, putting:
<programlisting>
\set HISTFILE ~/.psql_history- :DBNAME
</programlisting>
*************** bar
*** 3279,3286 ****
<term><varname>HISTSIZE</varname></term>
<listitem>
<para>
! The number of commands to store in the command history. The
! default value is 500.
</para>
<note>
<para>
--- 3316,3325 ----
<term><varname>HISTSIZE</varname></term>
<listitem>
<para>
! The maximum number of commands to store in the command history.
! If unset, at most 500 commands are stored by default.
! If set to a value that is negative or not an integer, no limit is
! applied.
</para>
<note>
<para>
*************** bar
*** 3297,3303 ****
<para>
The database server host you are currently connected to. This is
set every time you connect to a database (including program
! start-up), but can be unset.
</para>
</listitem>
</varlistentry>
--- 3336,3342 ----
<para>
The database server host you are currently connected to. This is
set every time you connect to a database (including program
! start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3350,3356 ****
generates an error, the error is ignored and the transaction
continues. When set to <literal>interactive</>, such errors are only
ignored in interactive sessions, and not when reading script
! files. When unset or set to <literal>off</>, a statement in a
transaction block that generates an error aborts the entire
transaction. The error rollback mode works by issuing an
implicit <command>SAVEPOINT</> for you, just before each command
--- 3389,3395 ----
generates an error, the error is ignored and the transaction
continues. When set to <literal>interactive</>, such errors are only
ignored in interactive sessions, and not when reading script
! files. When set to <literal>off</> (the default), a statement in a
transaction block that generates an error aborts the entire
transaction. The error rollback mode works by issuing an
implicit <command>SAVEPOINT</> for you, just before each command
*************** bar
*** 3385,3391 ****
<para>
The database server port to which you are currently connected.
This is set every time you connect to a database (including
! program start-up), but can be unset.
</para>
</listitem>
</varlistentry>
--- 3424,3430 ----
<para>
The database server port to which you are currently connected.
This is set every time you connect to a database (including
! program start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3458,3464 ****
<para>
The database user you are currently connected as. This is set
every time you connect to a database (including program
! start-up), but can be unset.
</para>
</listitem>
</varlistentry>
--- 3497,3503 ----
<para>
The database user you are currently connected as. This is set
every time you connect to a database (including program
! start-up), but can be changed or unset.
</para>
</listitem>
</varlistentry>
*************** bar
*** 3481,3487 ****
<listitem>
<para>
This variable is set at program start-up to
! reflect <application>psql</>'s version. It can be unset or changed.
</para>
</listitem>
</varlistentry>
--- 3520,3526 ----
<listitem>
<para>
This variable is set at program start-up to
! reflect <application>psql</>'s version. It can be changed or unset.
</para>
</listitem>
</varlistentry>
*************** PSQL_EDITOR_LINENUMBER_ARG='--line '
*** 4015,4020 ****
--- 4054,4060 ----
</para>
<para>
The location of the history file can be set explicitly via
+ the <varname>HISTFILE</varname> <application>psql</> variable or
the <envar>PSQL_HISTORY</envar> environment variable.
</para>
</listitem>
diff --git a/src/bin/psql/startup.c b/src/bin/psql/startup.c
index 0574b5b..a3654e6 100644
*** a/src/bin/psql/startup.c
--- b/src/bin/psql/startup.c
*************** main(int argc, char *argv[])
*** 166,175 ****
SetVariable(pset.vars, "VERSION", PG_VERSION_STR);
! /* Default values for variables */
SetVariableBool(pset.vars, "AUTOCOMMIT");
- SetVariable(pset.vars, "VERBOSITY", "default");
- SetVariable(pset.vars, "SHOW_CONTEXT", "errors");
SetVariable(pset.vars, "PROMPT1", DEFAULT_PROMPT1);
SetVariable(pset.vars, "PROMPT2", DEFAULT_PROMPT2);
SetVariable(pset.vars, "PROMPT3", DEFAULT_PROMPT3);
--- 166,173 ----
SetVariable(pset.vars, "VERSION", PG_VERSION_STR);
! /* Default values for variables (that don't match the result of \unset) */
SetVariableBool(pset.vars, "AUTOCOMMIT");
SetVariable(pset.vars, "PROMPT1", DEFAULT_PROMPT1);
SetVariable(pset.vars, "PROMPT2", DEFAULT_PROMPT2);
SetVariable(pset.vars, "PROMPT3", DEFAULT_PROMPT3);
*************** parse_psql_options(int argc, char *argv[
*** 578,594 ****
if (!equal_loc)
{
if (!DeleteVariable(pset.vars, value))
! {
! fprintf(stderr, _("%s: could not delete variable \"%s\"\n"),
! pset.progname, value);
! exit(EXIT_FAILURE);
! }
}
else
{
*equal_loc = '\0';
if (!SetVariable(pset.vars, value, equal_loc + 1))
! exit(EXIT_FAILURE);
}
free(value);
--- 576,588 ----
if (!equal_loc)
{
if (!DeleteVariable(pset.vars, value))
! exit(EXIT_FAILURE); /* error already printed */
}
else
{
*equal_loc = '\0';
if (!SetVariable(pset.vars, value, equal_loc + 1))
! exit(EXIT_FAILURE); /* error already printed */
}
free(value);
*************** showVersion(void)
*** 777,787 ****
/*
! * Assign hooks for psql variables.
*
* This isn't an amazingly good place for them, but neither is anywhere else.
*/
static bool
autocommit_hook(const char *newval)
{
--- 771,798 ----
/*
! * Substitute hooks and assign hooks for psql variables.
*
* This isn't an amazingly good place for them, but neither is anywhere else.
*/
+ static char *
+ bool_substitute_hook(char *newval)
+ {
+ if (newval == NULL)
+ {
+ /* "\unset FOO" becomes "\set FOO off" */
+ newval = pg_strdup("off");
+ }
+ else if (newval[0] == '\0')
+ {
+ /* "\set FOO" becomes "\set FOO on" */
+ pg_free(newval);
+ newval = pg_strdup("on");
+ }
+ return newval;
+ }
+
static bool
autocommit_hook(const char *newval)
{
*************** fetch_count_hook(const char *newval)
*** 822,833 ****
return true;
}
static bool
echo_hook(const char *newval)
{
! if (newval == NULL)
! pset.echo = PSQL_ECHO_NONE;
! else if (pg_strcasecmp(newval, "queries") == 0)
pset.echo = PSQL_ECHO_QUERIES;
else if (pg_strcasecmp(newval, "errors") == 0)
pset.echo = PSQL_ECHO_ERRORS;
--- 833,851 ----
return true;
}
+ static char *
+ echo_substitute_hook(char *newval)
+ {
+ if (newval == NULL)
+ newval = pg_strdup("none");
+ return newval;
+ }
+
static bool
echo_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "queries") == 0)
pset.echo = PSQL_ECHO_QUERIES;
else if (pg_strcasecmp(newval, "errors") == 0)
pset.echo = PSQL_ECHO_ERRORS;
*************** echo_hook(const char *newval)
*** 846,854 ****
static bool
echo_hidden_hook(const char *newval)
{
! if (newval == NULL)
! pset.echo_hidden = PSQL_ECHO_HIDDEN_OFF;
! else if (pg_strcasecmp(newval, "noexec") == 0)
pset.echo_hidden = PSQL_ECHO_HIDDEN_NOEXEC;
else
{
--- 864,871 ----
static bool
echo_hidden_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "noexec") == 0)
pset.echo_hidden = PSQL_ECHO_HIDDEN_NOEXEC;
else
{
*************** echo_hidden_hook(const char *newval)
*** 868,876 ****
static bool
on_error_rollback_hook(const char *newval)
{
! if (newval == NULL)
! pset.on_error_rollback = PSQL_ERROR_ROLLBACK_OFF;
! else if (pg_strcasecmp(newval, "interactive") == 0)
pset.on_error_rollback = PSQL_ERROR_ROLLBACK_INTERACTIVE;
else
{
--- 885,892 ----
static bool
on_error_rollback_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "interactive") == 0)
pset.on_error_rollback = PSQL_ERROR_ROLLBACK_INTERACTIVE;
else
{
*************** on_error_rollback_hook(const char *newva
*** 887,898 ****
return true;
}
static bool
comp_keyword_case_hook(const char *newval)
{
! if (newval == NULL)
! pset.comp_case = PSQL_COMP_CASE_PRESERVE_UPPER;
! else if (pg_strcasecmp(newval, "preserve-upper") == 0)
pset.comp_case = PSQL_COMP_CASE_PRESERVE_UPPER;
else if (pg_strcasecmp(newval, "preserve-lower") == 0)
pset.comp_case = PSQL_COMP_CASE_PRESERVE_LOWER;
--- 903,921 ----
return true;
}
+ static char *
+ comp_keyword_case_substitute_hook(char *newval)
+ {
+ if (newval == NULL)
+ newval = pg_strdup("preserve-upper");
+ return newval;
+ }
+
static bool
comp_keyword_case_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "preserve-upper") == 0)
pset.comp_case = PSQL_COMP_CASE_PRESERVE_UPPER;
else if (pg_strcasecmp(newval, "preserve-lower") == 0)
pset.comp_case = PSQL_COMP_CASE_PRESERVE_LOWER;
*************** comp_keyword_case_hook(const char *newva
*** 909,920 ****
return true;
}
static bool
histcontrol_hook(const char *newval)
{
! if (newval == NULL)
! pset.histcontrol = hctl_none;
! else if (pg_strcasecmp(newval, "ignorespace") == 0)
pset.histcontrol = hctl_ignorespace;
else if (pg_strcasecmp(newval, "ignoredups") == 0)
pset.histcontrol = hctl_ignoredups;
--- 932,950 ----
return true;
}
+ static char *
+ histcontrol_substitute_hook(char *newval)
+ {
+ if (newval == NULL)
+ newval = pg_strdup("none");
+ return newval;
+ }
+
static bool
histcontrol_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "ignorespace") == 0)
pset.histcontrol = hctl_ignorespace;
else if (pg_strcasecmp(newval, "ignoredups") == 0)
pset.histcontrol = hctl_ignoredups;
*************** prompt3_hook(const char *newval)
*** 952,963 ****
return true;
}
static bool
verbosity_hook(const char *newval)
{
! if (newval == NULL)
! pset.verbosity = PQERRORS_DEFAULT;
! else if (pg_strcasecmp(newval, "default") == 0)
pset.verbosity = PQERRORS_DEFAULT;
else if (pg_strcasecmp(newval, "terse") == 0)
pset.verbosity = PQERRORS_TERSE;
--- 982,1000 ----
return true;
}
+ static char *
+ verbosity_substitute_hook(char *newval)
+ {
+ if (newval == NULL)
+ newval = pg_strdup("default");
+ return newval;
+ }
+
static bool
verbosity_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "default") == 0)
pset.verbosity = PQERRORS_DEFAULT;
else if (pg_strcasecmp(newval, "terse") == 0)
pset.verbosity = PQERRORS_TERSE;
*************** verbosity_hook(const char *newval)
*** 974,985 ****
return true;
}
static bool
show_context_hook(const char *newval)
{
! if (newval == NULL)
! pset.show_context = PQSHOW_CONTEXT_ERRORS;
! else if (pg_strcasecmp(newval, "never") == 0)
pset.show_context = PQSHOW_CONTEXT_NEVER;
else if (pg_strcasecmp(newval, "errors") == 0)
pset.show_context = PQSHOW_CONTEXT_ERRORS;
--- 1011,1029 ----
return true;
}
+ static char *
+ show_context_substitute_hook(char *newval)
+ {
+ if (newval == NULL)
+ newval = pg_strdup("errors");
+ return newval;
+ }
+
static bool
show_context_hook(const char *newval)
{
! Assert(newval != NULL); /* else substitute hook messed up */
! if (pg_strcasecmp(newval, "never") == 0)
pset.show_context = PQSHOW_CONTEXT_NEVER;
else if (pg_strcasecmp(newval, "errors") == 0)
pset.show_context = PQSHOW_CONTEXT_ERRORS;
*************** EstablishVariableSpace(void)
*** 1002,1021 ****
{
pset.vars = CreateVariableSpace();
! SetVariableAssignHook(pset.vars, "AUTOCOMMIT", autocommit_hook);
! SetVariableAssignHook(pset.vars, "ON_ERROR_STOP", on_error_stop_hook);
! SetVariableAssignHook(pset.vars, "QUIET", quiet_hook);
! SetVariableAssignHook(pset.vars, "SINGLELINE", singleline_hook);
! SetVariableAssignHook(pset.vars, "SINGLESTEP", singlestep_hook);
! SetVariableAssignHook(pset.vars, "FETCH_COUNT", fetch_count_hook);
! SetVariableAssignHook(pset.vars, "ECHO", echo_hook);
! SetVariableAssignHook(pset.vars, "ECHO_HIDDEN", echo_hidden_hook);
! SetVariableAssignHook(pset.vars, "ON_ERROR_ROLLBACK", on_error_rollback_hook);
! SetVariableAssignHook(pset.vars, "COMP_KEYWORD_CASE", comp_keyword_case_hook);
! SetVariableAssignHook(pset.vars, "HISTCONTROL", histcontrol_hook);
! SetVariableAssignHook(pset.vars, "PROMPT1", prompt1_hook);
! SetVariableAssignHook(pset.vars, "PROMPT2", prompt2_hook);
! SetVariableAssignHook(pset.vars, "PROMPT3", prompt3_hook);
! SetVariableAssignHook(pset.vars, "VERBOSITY", verbosity_hook);
! SetVariableAssignHook(pset.vars, "SHOW_CONTEXT", show_context_hook);
}
--- 1046,1097 ----
{
pset.vars = CreateVariableSpace();
! SetVariableHooks(pset.vars, "AUTOCOMMIT",
! bool_substitute_hook,
! autocommit_hook);
! SetVariableHooks(pset.vars, "ON_ERROR_STOP",
! bool_substitute_hook,
! on_error_stop_hook);
! SetVariableHooks(pset.vars, "QUIET",
! bool_substitute_hook,
! quiet_hook);
! SetVariableHooks(pset.vars, "SINGLELINE",
! bool_substitute_hook,
! singleline_hook);
! SetVariableHooks(pset.vars, "SINGLESTEP",
! bool_substitute_hook,
! singlestep_hook);
! SetVariableHooks(pset.vars, "FETCH_COUNT",
! NULL,
! fetch_count_hook);
! SetVariableHooks(pset.vars, "ECHO",
! echo_substitute_hook,
! echo_hook);
! SetVariableHooks(pset.vars, "ECHO_HIDDEN",
! bool_substitute_hook,
! echo_hidden_hook);
! SetVariableHooks(pset.vars, "ON_ERROR_ROLLBACK",
! bool_substitute_hook,
! on_error_rollback_hook);
! SetVariableHooks(pset.vars, "COMP_KEYWORD_CASE",
! comp_keyword_case_substitute_hook,
! comp_keyword_case_hook);
! SetVariableHooks(pset.vars, "HISTCONTROL",
! histcontrol_substitute_hook,
! histcontrol_hook);
! SetVariableHooks(pset.vars, "PROMPT1",
! NULL,
! prompt1_hook);
! SetVariableHooks(pset.vars, "PROMPT2",
! NULL,
! prompt2_hook);
! SetVariableHooks(pset.vars, "PROMPT3",
! NULL,
! prompt3_hook);
! SetVariableHooks(pset.vars, "VERBOSITY",
! verbosity_substitute_hook,
! verbosity_hook);
! SetVariableHooks(pset.vars, "SHOW_CONTEXT",
! show_context_substitute_hook,
! show_context_hook);
}
diff --git a/src/bin/psql/variables.c b/src/bin/psql/variables.c
index 91e4ae8..b9b8fcb 100644
*** a/src/bin/psql/variables.c
--- b/src/bin/psql/variables.c
*************** CreateVariableSpace(void)
*** 52,57 ****
--- 52,58 ----
ptr = pg_malloc(sizeof *ptr);
ptr->name = NULL;
ptr->value = NULL;
+ ptr->substitute_hook = NULL;
ptr->assign_hook = NULL;
ptr->next = NULL;
*************** ParseVariableBool(const char *value, con
*** 101,111 ****
size_t len;
bool valid = true;
if (value == NULL)
! {
! *result = false; /* not set -> assume "off" */
! return valid;
! }
len = strlen(value);
--- 102,110 ----
size_t len;
bool valid = true;
+ /* Treat "unset" as an empty string, which will lead to error below */
if (value == NULL)
! value = "";
len = strlen(value);
*************** ParseVariableNum(const char *value, cons
*** 152,159 ****
char *end;
long numval;
if (value == NULL)
! return false;
errno = 0;
numval = strtol(value, &end, 0);
if (errno == 0 && *end == '\0' && end != value && numval == (int) numval)
--- 151,160 ----
char *end;
long numval;
+ /* Treat "unset" as an empty string, which will lead to error below */
if (value == NULL)
! value = "";
!
errno = 0;
numval = strtol(value, &end, 0);
if (errno == 0 && *end == '\0' && end != value && numval == (int) numval)
*************** SetVariable(VariableSpace space, const c
*** 235,247 ****
if (!valid_variable_name(name))
{
psql_error("invalid variable name: \"%s\"\n", name);
return false;
}
- if (!value)
- return DeleteVariable(space, name);
-
for (previous = space, current = space->next;
current;
previous = current, current = current->next)
--- 236,248 ----
if (!valid_variable_name(name))
{
+ /* Deletion of non-existent variable is not an error */
+ if (!value)
+ return true;
psql_error("invalid variable name: \"%s\"\n", name);
return false;
}
for (previous = space, current = space->next;
current;
previous = current, current = current->next)
*************** SetVariable(VariableSpace space, const c
*** 249,262 ****
if (strcmp(current->name, name) == 0)
{
/*
! * Found entry, so update, unless hook returns false. The hook
! * may need the passed value to have the same lifespan as the
! * variable, so allocate it right away, even though we'll have to
! * free it again if the hook returns false.
*/
! char *new_value = pg_strdup(value);
bool confirmed;
if (current->assign_hook)
confirmed = (*current->assign_hook) (new_value);
else
--- 250,269 ----
if (strcmp(current->name, name) == 0)
{
/*
! * Found entry, so update, unless assign hook returns false.
! *
! * We must duplicate the passed value to start with. This
! * simplifies the API for substitute hooks. Moreover, some assign
! * hooks assume that the passed value has the same lifespan as the
! * variable. Having to free the string again on failure is a
! * small price to pay for keeping these APIs simple.
*/
! char *new_value = value ? pg_strdup(value) : NULL;
bool confirmed;
+ if (current->substitute_hook)
+ new_value = (*current->substitute_hook) (new_value);
+
if (current->assign_hook)
confirmed = (*current->assign_hook) (new_value);
else
*************** SetVariable(VariableSpace space, const c
*** 267,305 ****
if (current->value)
pg_free(current->value);
current->value = new_value;
}
! else
pg_free(new_value); /* current->value is left unchanged */
return confirmed;
}
}
! /* not present, make new entry */
! current = pg_malloc(sizeof *current);
! current->name = pg_strdup(name);
! current->value = pg_strdup(value);
! current->assign_hook = NULL;
! current->next = NULL;
! previous->next = current;
return true;
}
/*
! * Attach an assign hook function to the named variable.
*
! * If the variable doesn't already exist, create it with value NULL,
! * just so we have a place to store the hook function. (Externally,
! * this isn't different from it not being defined.)
*
! * The hook is immediately called on the variable's current value. This is
! * meant to let it update any derived psql state. If the hook doesn't like
! * the current value, it will print a message to that effect, but we'll ignore
! * it. Generally we do not expect any such failure here, because this should
! * get called before any user-supplied value is assigned.
*/
void
! SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook)
{
struct _variable *current,
*previous;
--- 274,334 ----
if (current->value)
pg_free(current->value);
current->value = new_value;
+
+ /*
+ * If we deleted the value, and there are no hooks to
+ * remember, we can discard the variable altogether.
+ */
+ if (new_value == NULL &&
+ current->substitute_hook == NULL &&
+ current->assign_hook == NULL)
+ {
+ previous->next = current->next;
+ free(current->name);
+ free(current);
+ }
}
! else if (new_value)
pg_free(new_value); /* current->value is left unchanged */
return confirmed;
}
}
! /* not present, make new entry ... unless we were asked to delete */
! if (value)
! {
! current = pg_malloc(sizeof *current);
! current->name = pg_strdup(name);
! current->value = pg_strdup(value);
! current->substitute_hook = NULL;
! current->assign_hook = NULL;
! current->next = NULL;
! previous->next = current;
! }
return true;
}
/*
! * Attach substitute and/or assign hook functions to the named variable.
! * If you need only one hook, pass NULL for the other.
*
! * If the variable doesn't already exist, create it with value NULL, just so
! * we have a place to store the hook function(s). (The substitute hook might
! * immediately change the NULL to something else; if not, this state is
! * externally the same as the variable not being defined.)
*
! * The substitute hook, if given, is immediately called on the variable's
! * value. Then the assign hook, if given, is called on the variable's value.
! * This is meant to let it update any derived psql state. If the assign hook
! * doesn't like the current value, it will print a message to that effect,
! * but we'll ignore it. Generally we do not expect any such failure here,
! * because this should get called before any user-supplied value is assigned.
*/
void
! SetVariableHooks(VariableSpace space, const char *name,
! VariableSubstituteHook shook,
! VariableAssignHook ahook)
{
struct _variable *current,
*previous;
*************** SetVariableAssignHook(VariableSpace spac
*** 317,324 ****
if (strcmp(current->name, name) == 0)
{
/* found entry, so update */
! current->assign_hook = hook;
! (void) (*hook) (current->value);
return;
}
}
--- 346,357 ----
if (strcmp(current->name, name) == 0)
{
/* found entry, so update */
! current->substitute_hook = shook;
! current->assign_hook = ahook;
! if (shook)
! current->value = (*shook) (current->value);
! if (ahook)
! (void) (*ahook) (current->value);
return;
}
}
*************** SetVariableAssignHook(VariableSpace spac
*** 327,336 ****
current = pg_malloc(sizeof *current);
current->name = pg_strdup(name);
current->value = NULL;
! current->assign_hook = hook;
current->next = NULL;
previous->next = current;
! (void) (*hook) (NULL);
}
/*
--- 360,373 ----
current = pg_malloc(sizeof *current);
current->name = pg_strdup(name);
current->value = NULL;
! current->substitute_hook = shook;
! current->assign_hook = ahook;
current->next = NULL;
previous->next = current;
! if (shook)
! current->value = (*shook) (current->value);
! if (ahook)
! (void) (*ahook) (current->value);
}
/*
*************** SetVariableBool(VariableSpace space, con
*** 351,392 ****
bool
DeleteVariable(VariableSpace space, const char *name)
{
! struct _variable *current,
! *previous;
!
! if (!space)
! return true;
!
! for (previous = space, current = space->next;
! current;
! previous = current, current = current->next)
! {
! if (strcmp(current->name, name) == 0)
! {
! if (current->assign_hook)
! {
! /* Allow deletion only if hook is okay with NULL value */
! if (!(*current->assign_hook) (NULL))
! return false; /* message printed by hook */
! if (current->value)
! free(current->value);
! current->value = NULL;
! /* Don't delete entry, or we'd forget the hook function */
! }
! else
! {
! /* We can delete the entry as well as its value */
! if (current->value)
! free(current->value);
! previous->next = current->next;
! free(current->name);
! free(current);
! }
! return true;
! }
! }
!
! return true;
}
/*
--- 388,394 ----
bool
DeleteVariable(VariableSpace space, const char *name)
{
! return SetVariable(space, name, NULL);
}
/*
diff --git a/src/bin/psql/variables.h b/src/bin/psql/variables.h
index 274b4af..84be780 100644
*** a/src/bin/psql/variables.h
--- b/src/bin/psql/variables.h
***************
*** 18,29 ****
* prevent invalid values from being assigned, and can update internal C
* variables to keep them in sync with the variable's current value.
*
! * A hook function is called before any attempted assignment, with the
* proposed new value of the variable (or with NULL, if an \unset is being
* attempted). If it returns false, the assignment doesn't occur --- it
* should print an error message with psql_error() to tell the user why.
*
! * When a hook function is installed with SetVariableAssignHook(), it is
* called with the variable's current value (or with NULL, if it wasn't set
* yet). But its return value is ignored in this case. The hook should be
* set before any possibly-invalid value can be assigned.
--- 18,29 ----
* prevent invalid values from being assigned, and can update internal C
* variables to keep them in sync with the variable's current value.
*
! * An assign hook function is called before any attempted assignment, with the
* proposed new value of the variable (or with NULL, if an \unset is being
* attempted). If it returns false, the assignment doesn't occur --- it
* should print an error message with psql_error() to tell the user why.
*
! * When an assign hook function is installed with SetVariableHooks(), it is
* called with the variable's current value (or with NULL, if it wasn't set
* yet). But its return value is ignored in this case. The hook should be
* set before any possibly-invalid value can be assigned.
***************
*** 31,45 ****
typedef bool (*VariableAssignHook) (const char *newval);
/*
* Data structure representing one variable.
*
* Note: if value == NULL then the variable is logically unset, but we are
! * keeping the struct around so as not to forget about its hook function.
*/
struct _variable
{
char *name;
char *value;
VariableAssignHook assign_hook;
struct _variable *next;
};
--- 31,69 ----
typedef bool (*VariableAssignHook) (const char *newval);
/*
+ * Variables can also be given "substitute hook" functions. The substitute
+ * hook can replace values (including NULL) with other values, allowing
+ * normalization of variable contents. For example, for a boolean variable,
+ * we wish to interpret "\unset FOO" as "\set FOO off", and we can do that
+ * by installing a substitute hook. (We can use the same substitute hook
+ * for all bool or nearly-bool variables, which is why this responsibility
+ * isn't part of the assign hook.)
+ *
+ * The substitute hook is called before any attempted assignment, and before
+ * the assign hook if any, passing the proposed new value of the variable as a
+ * malloc'd string (or NULL, if an \unset is being attempted). It can return
+ * the same value, or a different malloc'd string, or modify the string
+ * in-place. It should free the passed-in value if it's not returning it.
+ * The substitute hook generally should not complain about erroneous values;
+ * that's a job for the assign hook.
+ *
+ * When a substitute hook is installed with SetVariableHooks(), it is applied
+ * to the variable's current value (typically NULL, if it wasn't set yet).
+ * That also happens before applying the assign hook.
+ */
+ typedef char *(*VariableSubstituteHook) (char *newval);
+
+ /*
* Data structure representing one variable.
*
* Note: if value == NULL then the variable is logically unset, but we are
! * keeping the struct around so as not to forget about its hook function(s).
*/
struct _variable
{
char *name;
char *value;
+ VariableSubstituteHook substitute_hook;
VariableAssignHook assign_hook;
struct _variable *next;
};
*************** int GetVariableNum(VariableSpace space,
*** 65,74 ****
void PrintVariables(VariableSpace space);
bool SetVariable(VariableSpace space, const char *name, const char *value);
- void SetVariableAssignHook(VariableSpace space, const char *name, VariableAssignHook hook);
bool SetVariableBool(VariableSpace space, const char *name);
bool DeleteVariable(VariableSpace space, const char *name);
void PsqlVarEnumError(const char *name, const char *value, const char *suggestions);
#endif /* VARIABLES_H */
--- 89,101 ----
void PrintVariables(VariableSpace space);
bool SetVariable(VariableSpace space, const char *name, const char *value);
bool SetVariableBool(VariableSpace space, const char *name);
bool DeleteVariable(VariableSpace space, const char *name);
+ void SetVariableHooks(VariableSpace space, const char *name,
+ VariableSubstituteHook shook,
+ VariableAssignHook ahook);
+
void PsqlVarEnumError(const char *name, const char *value, const char *suggestions);
#endif /* VARIABLES_H */
diff --git a/src/test/regress/expected/psql.out b/src/test/regress/expected/psql.out
index 420825a..026a4f0 100644
*** a/src/test/regress/expected/psql.out
--- b/src/test/regress/expected/psql.out
*************** invalid variable name: "invalid/name"
*** 11,16 ****
--- 11,33 ----
unrecognized value "foo" for "AUTOCOMMIT": boolean expected
\set FETCH_COUNT foo
invalid value "foo" for "FETCH_COUNT": integer expected
+ -- check handling of built-in boolean variable
+ \echo :ON_ERROR_ROLLBACK
+ off
+ \set ON_ERROR_ROLLBACK
+ \echo :ON_ERROR_ROLLBACK
+ on
+ \set ON_ERROR_ROLLBACK foo
+ unrecognized value "foo" for "ON_ERROR_ROLLBACK"
+ Available values are: on, off, interactive.
+ \echo :ON_ERROR_ROLLBACK
+ on
+ \set ON_ERROR_ROLLBACK on
+ \echo :ON_ERROR_ROLLBACK
+ on
+ \unset ON_ERROR_ROLLBACK
+ \echo :ON_ERROR_ROLLBACK
+ off
-- \gset
select 10 as test01, 20 as test02, 'Hello' as test03 \gset pref01_
\echo :pref01_test01 :pref01_test02 :pref01_test03
diff --git a/src/test/regress/sql/psql.sql b/src/test/regress/sql/psql.sql
index 79624b9..d823d11 100644
*** a/src/test/regress/sql/psql.sql
--- b/src/test/regress/sql/psql.sql
***************
*** 10,15 ****
--- 10,25 ----
-- fail: invalid value for special variable
\set AUTOCOMMIT foo
\set FETCH_COUNT foo
+ -- check handling of built-in boolean variable
+ \echo :ON_ERROR_ROLLBACK
+ \set ON_ERROR_ROLLBACK
+ \echo :ON_ERROR_ROLLBACK
+ \set ON_ERROR_ROLLBACK foo
+ \echo :ON_ERROR_ROLLBACK
+ \set ON_ERROR_ROLLBACK on
+ \echo :ON_ERROR_ROLLBACK
+ \unset ON_ERROR_ROLLBACK
+ \echo :ON_ERROR_ROLLBACK
-- \gset
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