Implemented support for virtual packages.

The patch adds 150 lines approximately. It is implemented by modifying
xbps_find_pkg_in_dict_by_name() and xbps_find_pkg_in_dict_by_pattern().

When no dictionary is returned if tries to find a virtual package by
looking at the "provides" array object, if found.

NEWS

@@ -1,5 +1,12 @@
 xbps-0.8.0 (???):
 
+ * Added support for virtual packages. A virtual package is one that doesn't
+   exist in the repository, but other packages can provide it. A new array
+   in the package properties dictionary has been added to specify which
+   virtual packages the package supports. As an example, the `rsyslog'
+   package provides the virtual package `syslog-daemon-0'. Other packages
+   can depend in `syslog-daemon>=0' and `rsyslog' will satisfy the dependency.
+
  * Merged the `progress_callback' branch that makes possible to specify a
    function callback to update progress while unpacking binary packages
    and while fetching files. xbps-bin(8) now reports a percentage while
@@ -11,13 +18,15 @@ xbps-0.8.0 (???):
    found in the first repository registered in the pool. It can also be used
    to find the newest version found in all registered repositories.
 
- * Improved package dependency sorting algorithm that uses less memory
+ * Improved package dependency sorting algorithm that uses less memory,
-   and as bonus sorts all packages in the way they should be (previously
+   it is 15% faster approximately and as bonus sorts all packages in the way
-   the sorting was a bit different for packages with no run-time dependencies).
+   they should be (previously the sorting was a bit different for packages
+   with no run-time dependencies).
 
- * Hide implementation details in the API, so the ABI is not compatible
+ * Many structural changes in the API. Made some stuff private and changed
-   anymore with previous versions. ABI will be respected once the API
+   some function arguments in the API, the ABI is not compatible anymore with
-   has been stabilized, but not for now.
+   previous versions... anyway you shouldn't be using libxbps just yet.
+   The API documentation has been modified to stay in sync with reality.
 
 xbps-0.7.3 (2011-01-16):
 

include/xbps_api.h

@@ -53,7 +53,7 @@
  * @def XBPS_RELVER
  * Current library release date.
  */
-#define XBPS_RELVER		"20110125"
+#define XBPS_RELVER		"20110126"
 
 /** 
  * @def XBPS_META_PATH
@@ -460,6 +460,26 @@ prop_dictionary_t xbps_find_pkg_from_plist(const char *plist,
 prop_dictionary_t xbps_find_pkg_dict_installed(const char *str,
 					       bool bypattern);
 
+/**
+ * Finds a package name matching an string object in a proplib array.
+ *
+ * @param[in] array The proplib array where to look for.
+ * @param[in] pkgname The package name to match.
+ *
+ * @return true on success, false otherwise and errno is set appropiately.
+ */
+bool xbps_find_pkgname_in_array(prop_array_t array, const char *pkgname);
+
+/**
+ * Finds a package pattern matching an string object in a proplib array.
+ *
+ * @param[in] array The proplib array where to look for.
+ * @param[in] pattern The package pattern to match.
+ *
+ * @return true on success, false otherwise and errno is set appropiately.
+ */
+bool xbps_find_pkgpattern_in_array(prop_array_t array, const char *pattern);
+
 /**
  * Finds a string matching an object in a proplib array.
  *

lib/plist.c

@@ -233,6 +233,37 @@ out:
 	return rpkgd;
 }
 
+static prop_dictionary_t
+find_virtual_pkg(prop_dictionary_t d,
+		 const char *key,
+		 const char *str,
+		 bool bypattern)
+{
+	prop_object_iterator_t iter;
+	prop_object_t obj;
+	prop_array_t provides;
+	bool found = false;
+
+	if ((iter = xbps_get_array_iter_from_dict(d, key)) == NULL)
+		return NULL;
+
+	while ((obj = prop_object_iterator_next(iter))) {
+		if ((provides = prop_dictionary_get(obj, "provides")) == NULL)
+			continue;
+
+		if (bypattern)
+			found = xbps_find_pkgpattern_in_array(provides, str);
+		else
+			found = xbps_find_pkgname_in_array(provides, str);
+
+		if (found)
+			break;
+	}
+	prop_object_iterator_release(iter);
+
+	return obj;
+}
+
 prop_dictionary_t
 xbps_find_pkg_in_dict_by_name(prop_dictionary_t dict,
 			      const char *key,
@@ -255,10 +286,17 @@ xbps_find_pkg_in_dict_by_name(prop_dictionary_t dict,
 			break;
 	}
 	prop_object_iterator_release(iter);
+	if (obj == NULL) {
+		/*
+		 * If a package couldn't be found by its name, try looking
+		 * for a package providing a virtual package, i.e "provides".
+		 */
+		obj = find_virtual_pkg(dict, key, pkgname, false);
 		if (obj == NULL) {
 			errno = ENOENT;
 			return NULL;
 		}
+	}
 
 	return obj;
 }
@@ -285,19 +323,90 @@ xbps_find_pkg_in_dict_by_pattern(prop_dictionary_t dict,
 			break;
 	}
 	prop_object_iterator_release(iter);
+	if (obj == NULL) {
+		/*
+		 * If a package couldn't be found by a pattern, try looking
+		 * for a package providing a virtual package pattern via
+		 * "provides".
+		 */
+		obj = find_virtual_pkg(dict, key, pattern, true);
 		if (obj == NULL) {
 			errno = ENOENT;
 			return NULL;
 		}
+	}
 
 	return obj;
 }
 
+bool
+xbps_find_pkgname_in_array(prop_array_t array, const char *pkgname)
+{
+	prop_object_iterator_t iter;
+	prop_object_t obj;
+	const char *pkgdep;
+	char *curpkgname;
+	bool found = false;
+
+	assert(array != NULL);
+	assert(pkgname != NULL);
+
+	iter = prop_array_iterator(array);
+	if (iter == NULL)
+		return false;
+
+	while ((obj = prop_object_iterator_next(iter))) {
+		assert(prop_object_type(obj) == PROP_TYPE_STRING);
+		pkgdep = prop_string_cstring_nocopy(obj);
+		curpkgname = xbps_get_pkg_name(pkgdep);
+		if (curpkgname == NULL)
+			break;
+		if (strcmp(curpkgname, pkgname) == 0) {
+			free(curpkgname);
+			found = true;
+			break;
+		}
+		free(curpkgname);
+	}
+	prop_object_iterator_release(iter);
+
+	return found;
+}
+
+bool
+xbps_find_pkgpattern_in_array(prop_array_t array, const char *pattern)
+{
+	prop_object_iterator_t iter;
+	prop_object_t obj;
+	const char *curpkgdep;
+	bool found = false;
+
+	assert(array != NULL);
+	assert(pattern != NULL);
+
+	iter = prop_array_iterator(array);
+	if (iter == NULL)
+		return false;
+
+	while ((obj = prop_object_iterator_next(iter))) {
+		assert(prop_object_type(obj) == PROP_TYPE_STRING);
+		curpkgdep = prop_string_cstring_nocopy(obj);
+		if (xbps_pkgpattern_match(curpkgdep, __UNCONST(pattern))) {
+			found = true;
+			break;
+		}
+	}
+	prop_object_iterator_release(iter);
+
+	return found;
+}
+
 bool
 xbps_find_string_in_array(prop_array_t array, const char *val)
 {
 	prop_object_iterator_t iter;
 	prop_object_t obj;
+	bool found = false;
 
 	assert(array != NULL);
 	assert(val != NULL);
@@ -307,17 +416,15 @@ xbps_find_string_in_array(prop_array_t array, const char *val)
 		return false;
 
 	while ((obj = prop_object_iterator_next(iter)) != NULL) {
-		if (prop_object_type(obj) != PROP_TYPE_STRING)
+		assert(prop_object_type(obj) == PROP_TYPE_STRING);
-			continue;
 		if (prop_string_equals_cstring(obj, val)) {
-			prop_object_iterator_release(iter);
+			found = true;
-			return true;
+			break;
 		}
 	}
-
 	prop_object_iterator_release(iter);
 
-	return false;
+	return found;
 }
 
 prop_object_iterator_t

lib/repository_pool.c

@@ -262,9 +262,6 @@ repo_find_pkg_cb(struct repository_pool_index *rpi, void *arg, bool *done)
 		errno = 0;
 		return 0;
 	}
-
-	xbps_dbg_printf("Didn't find '%s' (%s)\n",
-	    rpf->pattern, rpi->rpi_uri);
 	/* Not found */
 	errno = ENOENT;
 	return 0;