store: Added public functions to create and execute matchers.

The matcher types are now based on sdb_object_t to ease memory management in
case a matcher is used in multiple places. Constructors for each matcher type
are now available and the top-level matching function has been made public.

diff --git a/src/core/store_lookup.c b/src/core/store_lookup.c
index e0eedf00dc181587a97684f42ebaf35248f2f47c..305a513f14dcde6d7d01b54992c5ca24ce9dc39a 100644 (file)
--- a/src/core/store_lookup.c
+++ b/src/core/store_lookup.c
@@ -33,12 +33,14 @@
 
 #include "sysdb.h"
 #include "core/store-private.h"
+#include "core/object.h"
 
 #include <assert.h>
 
 #include <sys/types.h>
 #include <regex.h>
 
+#include <stdlib.h>
 #include <string.h>
 
 /*
@@ -47,30 +49,31 @@
 
 /* match the name of something */
 typedef struct {
-       const char *name;
-       regex_t    *name_re;
+       char    *name;
+       regex_t *name_re;
 } name_matcher_t;
 
 /* matcher base type */
-typedef struct {
+struct sdb_store_matcher {
+       sdb_object_t super;
        /* type of the matcher */
        int type;
-} matcher_t;
-#define M(m) ((matcher_t *)(m))
+};
+#define M(m) ((sdb_store_matcher_t *)(m))
 
 /* logical operator matcher */
 typedef struct {
-       matcher_t super;
+       sdb_store_matcher_t super;
 
        /* left and right hand operands */
-       matcher_t *left;
-       matcher_t *right;
+       sdb_store_matcher_t *left;
+       sdb_store_matcher_t *right;
 } op_matcher_t;
 #define OP_M(m) ((op_matcher_t *)(m))
 
 /* match any type of object by it's base information */
 typedef struct {
-       matcher_t super;
+       sdb_store_matcher_t super;
 
        /* match by the name of the object */
        name_matcher_t name;
@@ -109,9 +112,9 @@ typedef struct {
  */
 
 static int
-match_logical(matcher_t *m, sdb_store_base_t *obj);
+match_logical(sdb_store_matcher_t *m, sdb_store_base_t *obj);
 static int
-match_obj(matcher_t *m, sdb_store_base_t *obj);
+match_obj(sdb_store_matcher_t *m, sdb_store_base_t *obj);
 
 /* specific matchers */
 
@@ -244,7 +247,7 @@ enum {
        MATCHER_HOST,
 };
 
-typedef int (*matcher_cb)(matcher_t *, sdb_store_base_t *);
+typedef int (*matcher_cb)(sdb_store_matcher_t *, sdb_store_base_t *);
 
 /* this array needs to be indexable by the matcher types */
 static matcher_cb matchers[] = {
@@ -256,35 +259,25 @@ static matcher_cb matchers[] = {
 };
 
 static int
-match(matcher_t *m, sdb_store_base_t *obj)
-{
-       assert(m && obj);
-       assert((0 <= m->type)
-                       && ((size_t)m->type < SDB_STATIC_ARRAY_LEN(matchers)));
-
-       return matchers[m->type](m, obj);
-} /* match */
-
-static int
-match_logical(matcher_t *m, sdb_store_base_t *obj)
+match_logical(sdb_store_matcher_t *m, sdb_store_base_t *obj)
 {
        int status;
 
        assert(m && obj);
        assert(OP_M(m)->left && OP_M(m)->right);
 
-       status = match(OP_M(m)->left, obj);
+       status = sdb_store_matcher_matches(OP_M(m)->left, obj);
        /* lazy evaluation */
        if (status && (m->type == MATCHER_AND))
                return status;
        else if ((! status) && (m->type == MATCHER_OR))
                return status;
 
-       return match(OP_M(m)->right, obj);
+       return sdb_store_matcher_matches(OP_M(m)->right, obj);
 } /* match_logical */
 
 static int
-match_obj(matcher_t *m, sdb_store_base_t *obj)
+match_obj(sdb_store_matcher_t *m, sdb_store_base_t *obj)
 {
        int status;
 
@@ -308,5 +301,197 @@ match_obj(matcher_t *m, sdb_store_base_t *obj)
        return -1;
 } /* match_obj */
 
+/*
+ * private matcher types
+ */
+
+/* initializes a name matcher consuming two elements from ap */
+static int
+name_matcher_init(name_matcher_t *m, va_list ap)
+{
+       const char *name = va_arg(ap, const char *);
+       const char *name_re = va_arg(ap, const char *);
+
+       if (name) {
+               m->name = strdup(name);
+               if (! m->name)
+                       return -1;
+       }
+       if (name_re) {
+               m->name_re = malloc(sizeof(*m->name_re));
+               if (! m->name_re)
+                       return -1;
+               if (regcomp(m->name_re, name_re, REG_EXTENDED | REG_ICASE | REG_NOSUB))
+                       return -1;
+       }
+       return 0;
+} /* name_matcher_init */
+
+static void
+name_matcher_destroy(name_matcher_t *m)
+{
+       if (m->name)
+               free(m->name);
+       if (m->name_re) {
+               regfree(m->name_re);
+               free(m->name_re);
+       }
+} /* name_matcher_destroy */
+
+/* initializes an object matcher consuming two elements from ap */
+static int
+obj_matcher_init(sdb_object_t *obj, va_list ap)
+{
+       obj_matcher_t *m = OBJ_M(obj);
+       return name_matcher_init(&m->name, ap);
+} /* obj_matcher_init */
+
+static void
+obj_matcher_destroy(sdb_object_t *obj)
+{
+       obj_matcher_t *m = OBJ_M(obj);
+       name_matcher_destroy(&m->name);
+} /* obj_matcher_destroy */
+
+static int
+attr_matcher_init(sdb_object_t *obj, va_list ap)
+{
+       attr_matcher_t *attr = ATTR_M(obj);
+       int status;
+
+       M(obj)->type = MATCHER_ATTR;
+
+       status = obj_matcher_init(obj, ap);
+       if (! status)
+               status = name_matcher_init(&attr->value, ap);
+       return status;
+} /* attr_matcher_init */
+
+static void
+attr_matcher_destroy(sdb_object_t *obj)
+{
+       attr_matcher_t *attr = ATTR_M(obj);
+
+       obj_matcher_destroy(obj);
+       name_matcher_destroy(&attr->value);
+} /* attr_matcher_destroy */
+
+static int
+service_matcher_init(sdb_object_t *obj, va_list ap)
+{
+       attr_matcher_t *attr;
+       int status;
+
+       M(obj)->type = MATCHER_SERVICE;
+
+       status = obj_matcher_init(obj, ap);
+       if (status)
+               return status;
+
+       attr = va_arg(ap, attr_matcher_t *);
+
+       sdb_object_ref(SDB_OBJ(attr));
+       SERVICE_M(obj)->attr = attr;
+       return 0;
+} /* service_matcher_init */
+
+static void
+service_matcher_destroy(sdb_object_t *obj)
+{
+       obj_matcher_destroy(obj);
+       sdb_object_deref(SDB_OBJ(SERVICE_M(obj)->attr));
+} /* service_matcher_destroy */
+
+static int
+host_matcher_init(sdb_object_t *obj, va_list ap)
+{
+       service_matcher_t *service;
+       attr_matcher_t *attr;
+       int status;
+
+       M(obj)->type = MATCHER_HOST;
+
+       status = obj_matcher_init(obj, ap);
+       if (status)
+               return status;
+
+       service = va_arg(ap, service_matcher_t *);
+       attr = va_arg(ap, attr_matcher_t *);
+
+       sdb_object_ref(SDB_OBJ(service));
+       HOST_M(obj)->service = service;
+       sdb_object_ref(SDB_OBJ(attr));
+       HOST_M(obj)->attr = attr;
+       return 0;
+} /* host_matcher_init */
+
+static void
+host_matcher_destroy(sdb_object_t *obj)
+{
+       obj_matcher_destroy(obj);
+       sdb_object_deref(SDB_OBJ(HOST_M(obj)->service));
+       sdb_object_deref(SDB_OBJ(HOST_M(obj)->attr));
+} /* host_matcher_destroy */
+
+static sdb_type_t attr_type = {
+       /* size = */ sizeof(attr_matcher_t),
+       /* init = */ attr_matcher_init,
+       /* destroy = */ attr_matcher_destroy,
+};
+
+static sdb_type_t service_type = {
+       /* size = */ sizeof(service_matcher_t),
+       /* init = */ service_matcher_init,
+       /* destroy = */ service_matcher_destroy,
+};
+
+static sdb_type_t host_type = {
+       /* size = */ sizeof(host_matcher_t),
+       /* init = */ host_matcher_init,
+       /* destroy = */ host_matcher_destroy,
+};
+
+/*
+ * public API
+ */
+
+sdb_store_matcher_t *
+sdb_store_attr_matcher(const char *attr_name, const char *attr_name_re,
+               const char *attr_value, const char *attr_value_re)
+{
+       return M(sdb_object_create("attr-matcher", attr_type,
+                               attr_name, attr_name_re, attr_value, attr_value_re));
+} /* sdb_store_attr_matcher */
+
+sdb_store_matcher_t *
+sdb_store_service_matcher(const char *service_name, const char *service_name_re,
+               sdb_store_matcher_t *attr_matcher)
+{
+       return M(sdb_object_create("service-matcher", service_type,
+                               service_name, service_name_re, attr_matcher));
+} /* sdb_store_service_matcher */
+
+sdb_store_matcher_t *
+sdb_store_host_matcher(const char *host_name, const char *host_name_re,
+               sdb_store_matcher_t *service_matcher,
+               sdb_store_matcher_t *attr_matcher)
+{
+       return M(sdb_object_create("host-matcher", host_type,
+                               host_name, host_name_re, service_matcher, attr_matcher));
+} /* sdb_store_host_matcher */
+
+int
+sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_base_t *obj)
+{
+       /* "NULL" always matches */
+       if ((! m) || (! obj))
+               return 0;
+
+       if ((m->type < 0) || ((size_t)m->type >= SDB_STATIC_ARRAY_LEN(matchers)))
+               return -1;
+
+       return matchers[m->type](m, obj);
+} /* sdb_store_matcher_matches */
+
 /* vim: set tw=78 sw=4 ts=4 noexpandtab : */
 

diff --git a/src/include/core/store.h b/src/include/core/store.h
index f2e210da1723eda40e62f5b7ef2d086ba26d00e5..a327ae9d31ebd31744e4ce6d9d0786b0d183ae29 100644 (file)
--- a/src/include/core/store.h
+++ b/src/include/core/store.h
@@ -127,6 +127,58 @@ int
 sdb_store_service(const char *hostname, const char *name,
                sdb_time_t last_update);
 
+/*
+ * Store matchers may be used to lookup objects from the host based on their
+ * various attributes. Each type of matcher evaluates attributes of the
+ * respective object type.
+ *
+ * For each matcher object, *all* specified attributes have to match.
+ *
+ * A store matcher object inherits from sdb_object_t and, thus, may safely be
+ * cast to a generic object.
+ */
+struct sdb_store_matcher;
+typedef struct sdb_store_matcher sdb_store_matcher_t;
+
+/*
+ * sdb_store_attr_matcher:
+ * Creates a matcher matching attributes based on their name or value. Either
+ * a complete name (which will have to match completely but case-independent)
+ * or an extended POSIX regular expression may be specified.
+ */
+sdb_store_matcher_t *
+sdb_store_attr_matcher(const char *attr_name, const char *attr_name_re,
+               const char *attr_value, const char *attr_value_re);
+
+/*
+ * sdb_store_service_matcher:
+ * Creates a matcher matching services based on their name or attributes.
+ */
+sdb_store_matcher_t *
+sdb_store_service_matcher(const char *service_name, const char *service_name_re,
+               sdb_store_matcher_t *attr_matcher);
+
+/*
+ * sdb_store_host_matcher:
+ * Creates a matcher matching hosts based on their name, services assigned to
+ * the host, or its attributes.
+ */
+sdb_store_matcher_t *
+sdb_store_host_matcher(const char *host_name, const char *host_name_re,
+               sdb_store_matcher_t *service_matcher,
+               sdb_store_matcher_t *attr_matcher);
+
+/*
+ * sdb_store_matcher_matches:
+ * Check whether the specified matcher matches the specified store object.
+ *
+ * Returns:
+ *  - 0 if the object matches
+ *  - a negative value else
+ */
+int
+sdb_store_matcher_matches(sdb_store_matcher_t *m, sdb_store_base_t *obj);
+
 /*
  * Flags for serialization functions.
  *