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authorTom Lane2017-03-13 21:14:46 +0000
committerTom Lane2017-03-13 21:14:46 +0000
commit895e36bb3f36fdb7ec8e573be1a20d104fac820b (patch)
tree0174e31cf8b59bc4ae31f314f323642bcc06bda7
parent1c7a66a8e9378aeb092d7ed26890134d17fdd691 (diff)
Add a "void *" passthrough pointer for psqlscan.l's callback functions.
The immediate motivation for this is to provide clean infrastructure for the proposed \if...\endif patch for psql; but it seems like a good thing to have even if that patch doesn't get in. Previously the callback functions could only make use of application-global state, which is a pretty severe handicap. For the moment, the pointer is only passed through to the get_variable callback function. I considered also passing it to the write_error callback, but for now let's not. Neither psql nor pgbench has a use for that, and in the case of psql we'd have to invent a separate wrapper function because we would certainly not want to change the signature of psql_error(). Discussion: https://postgr.es/m/[email protected]
-rw-r--r--src/bin/psql/common.c6
-rw-r--r--src/bin/psql/common.h3
-rw-r--r--src/bin/psql/psqlscanslash.l3
-rw-r--r--src/fe_utils/psqlscan.l19
-rw-r--r--src/include/fe_utils/psqlscan.h5
-rw-r--r--src/include/fe_utils/psqlscan_int.h4
6 files changed, 33 insertions, 7 deletions
diff --git a/src/bin/psql/common.c b/src/bin/psql/common.c
index 1aa56ab3a2..e9d4fe6786 100644
--- a/src/bin/psql/common.c
+++ b/src/bin/psql/common.c
@@ -119,9 +119,13 @@ setQFout(const char *fname)
* If "escape" is true, return the value suitably quoted and escaped,
* as an identifier or string literal depending on "as_ident".
* (Failure in escaping should lead to returning NULL.)
+ *
+ * "passthrough" is the pointer previously given to psql_scan_set_passthrough.
+ * psql currently doesn't use this.
*/
char *
-psql_get_variable(const char *varname, bool escape, bool as_ident)
+psql_get_variable(const char *varname, bool escape, bool as_ident,
+ void *passthrough)
{
char *result;
const char *value;
diff --git a/src/bin/psql/common.h b/src/bin/psql/common.h
index a83bc69ab7..3d8b8da7fe 100644
--- a/src/bin/psql/common.h
+++ b/src/bin/psql/common.h
@@ -16,7 +16,8 @@
extern bool openQueryOutputFile(const char *fname, FILE **fout, bool *is_pipe);
extern bool setQFout(const char *fname);
-extern char *psql_get_variable(const char *varname, bool escape, bool as_ident);
+extern char *psql_get_variable(const char *varname, bool escape, bool as_ident,
+ void *passthrough);
extern void psql_error(const char *fmt,...) pg_attribute_printf(1, 2);
diff --git a/src/bin/psql/psqlscanslash.l b/src/bin/psql/psqlscanslash.l
index 5b7953bf7b..ba4a08d000 100644
--- a/src/bin/psql/psqlscanslash.l
+++ b/src/bin/psql/psqlscanslash.l
@@ -243,7 +243,8 @@ other .
yyleng - 1);
value = cur_state->callbacks->get_variable(varname,
false,
- false);
+ false,
+ cur_state->cb_passthrough);
free(varname);
/*
diff --git a/src/fe_utils/psqlscan.l b/src/fe_utils/psqlscan.l
index 1b29341fa8..19b3e57aa4 100644
--- a/src/fe_utils/psqlscan.l
+++ b/src/fe_utils/psqlscan.l
@@ -700,7 +700,8 @@ other .
if (cur_state->callbacks->get_variable)
value = cur_state->callbacks->get_variable(varname,
false,
- false);
+ false,
+ cur_state->cb_passthrough);
else
value = NULL;
@@ -923,6 +924,19 @@ psql_scan_destroy(PsqlScanState state)
}
/*
+ * Set the callback passthrough pointer for the lexer.
+ *
+ * This could have been integrated into psql_scan_create, but keeping it
+ * separate allows the application to change the pointer later, which might
+ * be useful.
+ */
+void
+psql_scan_set_passthrough(PsqlScanState state, void *passthrough)
+{
+ state->cb_passthrough = passthrough;
+}
+
+/*
* Set up to perform lexing of the given input line.
*
* The text at *line, extending for line_len bytes, will be scanned by
@@ -1409,7 +1423,8 @@ psqlscan_escape_variable(PsqlScanState state, const char *txt, int len,
/* Variable lookup. */
varname = psqlscan_extract_substring(state, txt + 2, len - 3);
if (state->callbacks->get_variable)
- value = state->callbacks->get_variable(varname, true, as_ident);
+ value = state->callbacks->get_variable(varname, true, as_ident,
+ state->cb_passthrough);
else
value = NULL;
free(varname);
diff --git a/src/include/fe_utils/psqlscan.h b/src/include/fe_utils/psqlscan.h
index 21c4f227a1..0cc632b821 100644
--- a/src/include/fe_utils/psqlscan.h
+++ b/src/include/fe_utils/psqlscan.h
@@ -53,7 +53,8 @@ typedef struct PsqlScanCallbacks
{
/* Fetch value of a variable, as a pfree'able string; NULL if unknown */
/* This pointer can be NULL if no variable substitution is wanted */
- char *(*get_variable) (const char *varname, bool escape, bool as_ident);
+ char *(*get_variable) (const char *varname, bool escape,
+ bool as_ident, void *passthrough);
/* Print an error message someplace appropriate */
/* (very old gcc versions don't support attributes on function pointers) */
#if defined(__GNUC__) && __GNUC__ < 4
@@ -67,6 +68,8 @@ typedef struct PsqlScanCallbacks
extern PsqlScanState psql_scan_create(const PsqlScanCallbacks *callbacks);
extern void psql_scan_destroy(PsqlScanState state);
+extern void psql_scan_set_passthrough(PsqlScanState state, void *passthrough);
+
extern void psql_scan_setup(PsqlScanState state,
const char *line, int line_len,
int encoding, bool std_strings);
diff --git a/src/include/fe_utils/psqlscan_int.h b/src/include/fe_utils/psqlscan_int.h
index 0fddc7a856..b4044e806a 100644
--- a/src/include/fe_utils/psqlscan_int.h
+++ b/src/include/fe_utils/psqlscan_int.h
@@ -115,9 +115,11 @@ typedef struct PsqlScanStateData
char *dolqstart; /* current $foo$ quote start string */
/*
- * Callback functions provided by the program making use of the lexer.
+ * Callback functions provided by the program making use of the lexer,
+ * plus a void* callback passthrough argument.
*/
const PsqlScanCallbacks *callbacks;
+ void *cb_passthrough;
} PsqlScanStateData;