From: Sebastian Harl <sh@tokkee.org>
Date: Sun, 20 Jul 2014 18:55:44 +0000 (+0200)
Subject: store, frontend: Added support for matching NULL attributes.
X-Git-Tag: sysdb-0.3.0~41
X-Git-Url: https://git.tokkee.org/?p=sysdb.git;a=commitdiff_plain;h=444db0c3fae176a18166120dd19a7e01ee95823c

store, frontend: Added support for matching NULL attributes.

This matches any hosts which are missing the specified attribute.
---

diff --git a/src/core/store-private.h b/src/core/store-private.h
index c7d99f9..a2121f4 100644
--- a/src/core/store-private.h
+++ b/src/core/store-private.h
@@ -123,6 +123,7 @@ enum {
 	MATCHER_EQ,
 	MATCHER_GE,
 	MATCHER_GT,
+	MATCHER_ISNULL,
 };
 
 #define MATCHER_SYM(t) \
@@ -136,6 +137,7 @@ enum {
 		: ((t) == MATCHER_EQ) ? "=" \
 		: ((t) == MATCHER_GE) ? ">=" \
 		: ((t) == MATCHER_GT) ? ">" \
+		: ((t) == MATCHER_ISNULL) ? "IS NULL" \
 		: "UNKNOWN")
 
 /* match the name of something */
@@ -188,6 +190,12 @@ typedef struct {
 } attr_matcher_t;
 #define ATTR_M(m) ((attr_matcher_t *)(m))
 
+typedef struct {
+	sdb_store_matcher_t super;
+	char *attr_name; /* we only support matching attributes */
+} isnull_matcher_t;
+#define ISNULL_M(m) ((isnull_matcher_t *)(m))
+
 /* match using conditionals */
 typedef struct {
 	sdb_store_matcher_t super;
diff --git a/src/core/store_lookup.c b/src/core/store_lookup.c
index 7e2acef..557b936 100644
--- a/src/core/store_lookup.c
+++ b/src/core/store_lookup.c
@@ -254,11 +254,19 @@ match_gt(sdb_store_matcher_t *m, sdb_host_t *host)
 	return (status != INT_MAX) && (status > 0);
 } /* match_gt */
 
+static int
+match_isnull(sdb_store_matcher_t *m, sdb_host_t *host)
+{
+	assert(m->type == MATCHER_ISNULL);
+	return attr_get(host, ISNULL_M(m)->attr_name) == NULL;
+} /* match_isnull */
+
 typedef int (*matcher_cb)(sdb_store_matcher_t *, sdb_host_t *);
 
 /* this array needs to be indexable by the matcher types;
  * -> update the enum in store-private.h when updating this */
-static matcher_cb matchers[] = {
+static matcher_cb
+matchers[] = {
 	match_logical,
 	match_logical,
 	match_unary,
@@ -269,6 +277,7 @@ static matcher_cb matchers[] = {
 	match_eq,
 	match_ge,
 	match_gt,
+	match_isnull,
 };
 
 /*
@@ -542,6 +551,39 @@ uop_tostring(sdb_store_matcher_t *m, char *buf, size_t buflen)
 	return buf;
 } /* uop_tostring */
 
+static int
+isnull_matcher_init(sdb_object_t *obj, va_list ap)
+{
+	const char *name;
+
+	M(obj)->type = va_arg(ap, int);
+	if (M(obj)->type != MATCHER_ISNULL)
+		return -1;
+
+	name = va_arg(ap, const char *);
+	if (! name)
+		return -1;
+	ISNULL_M(obj)->attr_name = strdup(name);
+	if (! ISNULL_M(obj)->attr_name)
+		return -1;
+	return 0;
+} /* isnull_matcher_init */
+
+static void
+isnull_matcher_destroy(sdb_object_t *obj)
+{
+	if (ISNULL_M(obj)->attr_name)
+		free(ISNULL_M(obj)->attr_name);
+	ISNULL_M(obj)->attr_name = NULL;
+} /* isnull_matcher_destroy */
+
+static char *
+isnull_tostring(sdb_store_matcher_t *m, char *buf, size_t buflen)
+{
+	snprintf(buf, buflen, "(IS NULL, attr.%s)", ISNULL_M(m)->attr_name);
+	return buf;
+} /* isnull_tostring */
+
 static sdb_type_t name_type = {
 	/* size = */ sizeof(name_matcher_t),
 	/* init = */ name_matcher_init,
@@ -572,11 +614,18 @@ static sdb_type_t uop_type = {
 	/* destroy = */ uop_matcher_destroy,
 };
 
+static sdb_type_t isnull_type = {
+	/* size = */ sizeof(isnull_matcher_t),
+	/* init = */ isnull_matcher_init,
+	/* destroy = */ isnull_matcher_destroy,
+};
+
 typedef char *(*matcher_tostring_cb)(sdb_store_matcher_t *, char *, size_t);
 
 /* this array needs to be indexable by the matcher types;
  * -> update the enum in store-private.h when updating this */
-static matcher_tostring_cb matchers_tostring[] = {
+static matcher_tostring_cb
+matchers_tostring[] = {
 	op_tostring,
 	op_tostring,
 	uop_tostring,
@@ -587,6 +636,7 @@ static matcher_tostring_cb matchers_tostring[] = {
 	cond_tostring,
 	cond_tostring,
 	cond_tostring,
+	isnull_tostring,
 };
 
 /*
@@ -667,6 +717,13 @@ sdb_store_gt_matcher(sdb_store_cond_t *cond)
 				MATCHER_GT, cond));
 } /* sdb_store_gt_matcher */
 
+sdb_store_matcher_t *
+sdb_store_isnull_matcher(const char *attr_name)
+{
+	return M(sdb_object_create("isnull-matcher", isnull_type,
+				MATCHER_ISNULL, attr_name));
+} /* sdb_store_isnull_matcher */
+
 static sdb_store_matcher_t *
 parse_attr_cmp(const char *attr, const char *op, const sdb_data_t *value)
 {
@@ -680,7 +737,11 @@ parse_attr_cmp(const char *attr, const char *op, const sdb_data_t *value)
 	if (! strcasecmp(attr, "name"))
 		return NULL;
 
-	if (! strcasecmp(op, "<"))
+	if (! strcasecmp(op, "IS"))
+		return sdb_store_isnull_matcher(attr);
+	else if (! value)
+		return NULL;
+	else if (! strcasecmp(op, "<"))
 		matcher = sdb_store_lt_matcher;
 	else if (! strcasecmp(op, "<="))
 		matcher = sdb_store_le_matcher;
diff --git a/src/frontend/grammar.y b/src/frontend/grammar.y
index 34a9c6b..2173e6d 100644
--- a/src/frontend/grammar.y
+++ b/src/frontend/grammar.y
@@ -81,10 +81,13 @@ sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
 
 %token SCANNER_ERROR
 
-%token AND OR NOT WHERE
+%token AND OR IS NOT WHERE
 %token CMP_EQUAL CMP_NEQUAL CMP_REGEX CMP_NREGEX
 %token CMP_LT CMP_LE CMP_GE CMP_GT
 
+/* NULL token */
+%token NULL_T
+
 %token FETCH LIST LOOKUP
 
 %token <str> IDENTIFIER STRING
@@ -97,7 +100,8 @@ sdb_fe_yyerror(YYLTYPE *lval, sdb_fe_yyscan_t scanner, const char *msg);
 %right NOT
 %left CMP_EQUAL CMP_NEQUAL
 %left CMP_LT CMP_LE CMP_GE CMP_GT
-%left CMP_REGEX CMP_NREGEX
+%nonassoc CMP_REGEX CMP_NREGEX
+%nonassoc IS
 %left '(' ')'
 %left '.'
 
@@ -305,6 +309,25 @@ compare_matcher:
 			free($3); $3 = NULL;
 			sdb_data_free_datum(&$5);
 		}
+	|
+	IDENTIFIER '.' IDENTIFIER IS NULL_T
+		{
+			$$ = sdb_store_matcher_parse_cmp($1, $3, "IS", NULL);
+			free($1); $1 = NULL;
+			free($3); $3 = NULL;
+		}
+	|
+	IDENTIFIER '.' IDENTIFIER IS NOT NULL_T
+		{
+			sdb_store_matcher_t *m;
+			m = sdb_store_matcher_parse_cmp($1, $3, "IS", NULL);
+			free($1); $1 = NULL;
+			free($3); $3 = NULL;
+
+			/* sdb_store_inv_matcher return NULL if m==NULL */
+			$$ = sdb_store_inv_matcher(m);
+			sdb_object_deref(SDB_OBJ(m));
+		}
 	;
 
 op:
diff --git a/src/frontend/scanner.l b/src/frontend/scanner.l
index 0396db5..a7b72b4 100644
--- a/src/frontend/scanner.l
+++ b/src/frontend/scanner.l
@@ -108,12 +108,16 @@ float		({float1}|{float2}|{float3}|{float4}|{float5})
 			return AND;
 		else if (! strcasecmp(yytext, "FETCH"))
 			return FETCH;
+		else if (! strcasecmp(yytext, "IS"))
+			return IS;
 		else if (! strcasecmp(yytext, "LIST"))
 			return LIST;
 		else if (! strcasecmp(yytext, "LOOKUP"))
 			return LOOKUP;
 		else if (! strcasecmp(yytext, "NOT"))
 			return NOT;
+		else if (! strcasecmp(yytext, "NULL"))
+			return NULL_T;
 		else if (! strcasecmp(yytext, "OR"))
 			return OR;
 		else if (! strcasecmp(yytext, "WHERE"))
diff --git a/src/include/core/store.h b/src/include/core/store.h
index aa28c96..7a9dc44 100644
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -209,6 +209,13 @@ sdb_store_name_matcher(int type, const char *name, _Bool re);
 sdb_store_matcher_t *
 sdb_store_attr_matcher(const char *name, const char *value, _Bool re);
 
+/*
+ * sdb_store_isnull_matcher:
+ * Creates a matcher matching "missing" attributes.
+ */
+sdb_store_matcher_t *
+sdb_store_isnull_matcher(const char *attr_name);
+
 /*
  * sdb_store_lt_matcher, sdb_store_le_matcher, sdb_store_eq_matcher,
  * sdb_store_ge_matcher, sdb_store_gt_matcher:
diff --git a/t/unit/frontend/parser_test.c b/t/unit/frontend/parser_test.c
index 8c62660..4b9b672 100644
--- a/t/unit/frontend/parser_test.c
+++ b/t/unit/frontend/parser_test.c
@@ -106,6 +106,22 @@ START_TEST(test_parse)
 		  "attribute.foo = "
 		  "-12e+3",              -1,  1, CONNECTION_LOOKUP },
 
+		/* NULL */
+		{ "LOOKUP hosts WHERE "
+		  "attribute.foo "
+		  "IS NULL",             -1,  1, CONNECTION_LOOKUP },
+		{ "LOOKUP hosts WHERE "
+		  "attribute.foo "
+		  "IS NOT NULL",         -1,  1, CONNECTION_LOOKUP },
+		{ "LOOKUP hosts WHERE "
+		  "NOT attribute.foo "
+		  "IS NULL",             -1,  1, CONNECTION_LOOKUP },
+		{ "LOOKUP hosts WHERE "
+		  "host.name IS NULL",   -1, -1, 0 },
+		{ "LOOKUP hosts WHERE "
+		  "service.name "
+		  "IS NULL",             -1, -1, 0 },
+
 		/* invalid numeric constants */
 		{ "LOOKUP hosts WHERE "
 		  "attribute.foo = "
@@ -210,6 +226,16 @@ START_TEST(test_parse_matcher)
 		{ "host.name =~ 'pattern' OR "
 		  "service.name =~ 'pattern'",      -1,  MATCHER_OR },
 		{ "NOT host.name = 'host'",         -1,  MATCHER_NOT },
+		/* numeric expressions */
+		{ "attribute.foo < 123",            -1,  MATCHER_LT },
+		{ "attribute.foo <= 123",           -1,  MATCHER_LE },
+		{ "attribute.foo = 123",            -1,  MATCHER_EQ },
+		{ "attribute.foo >= 123",           -1,  MATCHER_GE },
+		{ "attribute.foo > 123",            -1,  MATCHER_GT },
+		/* NULL; while this is an implementation detail,
+		 * IS NULL currently maps to an equality matcher */
+		{ "attribute.foo IS NULL",          -1,  MATCHER_ISNULL },
+		{ "attribute.foo IS NOT NULL",      -1,  MATCHER_NOT },
 
 		/* check operator precedence */
 		{ "host.name = 'name' OR "