PERFORCE change 125164 for review

[Garrett Cooper]

http://perforce.freebsd.org/chv.cgi?CH=125164

Change 125164 by gcooper at optimus-revised_pkgtools on 2007/08/15 05:59:15

	Filling in more blanks with the BDB DB API.

Affected files ...

.. //depot/projects/soc2007/revised_fbsd_pkgtools/v2/lib/db/api.c#2 edit
.. //depot/projects/soc2007/revised_fbsd_pkgtools/v2/lib/db/api.h#2 edit

Differences ...

==== //depot/projects/soc2007/revised_fbsd_pkgtools/v2/lib/db/api.c#2 (text+ko) ====

@@ -1,42 +1,229 @@
 #include "lib/db/api.h"
 
+/**
+ * @brief: Merge +CONTENTS information or similar output into file database
+ * @return 0 on success
+ * @return 1 on failure
+ */
+int
+build_filedb(DB *database, const char *filedb_filename, const char **file_manifest_filenames)
+{
+
+    int build_db_exit_status;
+
+    /**
+     * Create temporary store for output conversion,
+     * and convert.
+     */
+    char *file_data;
+
+    /**
+     * Convert all entries to strings.
+     */
+    build_db_exit_status = build_db(database, filedb_filename, file_data);
+
+    return build_db_exit_status;
+
+}
+
+/**
+ * @brief Merge INDEX information into pkg database.
+ * @return 0 on success
+ * @return 1 on failure
+ */
 int
-build_filedb(DB *database, const char *filedb_filename, const char *file_manifest_filename)
+build_pkgdb(DB *database, const char *pkgdb_filename, const char **index_filenames)
 {
 
+    int build_db_exit_status;
+
+    /**
+     * Create temporary store for output conversion,
+     * and convert.
+     */
+    char *pkg_data;
 
+    /**
+     * Convert all entries to strings.
+     */
+    build_db_exit_status = build_db(database, pkgdb_filename, pkg_data);
 
+    return build_db_exit_status;
 
 }
 
+/**
+ * @brief Create a database by first creating the header, then the
+ * cache, and return the database.
+ * @return 0 on success
+ * @return 1 on failure
+ */
 int
-build_pkgdb(DB *database, const char *pkgdb_filename, const char *index_filename)
+build_db(DB *database, const char *db_filename, const char *data)
 {
 
+    int build_db_exit_status;
+	
+    build_db_exit_status =
+	dbopen(db_filename, O_CREAT | O_EXLOCK | O_EXCL | O_WRLOCK, 0644, DB_HASH, NULL);
+
+    /**
+     * dbopen was successful.
+     */
+    if(0 == build_db_exit_status) {
+
+	/**
+	 * Try initializing the database header.
+	 */
+	build_db_exit_status = initialize_database_header(database);
+
+	/**
+	 * Database header creation was good. Continue by trying to
+	 * create the cache.
+	 */
+	if(0 == build_db_exit_status) {
+
+	    build_db_exit_status = initialize_entry_cache(database);
+
+	    /**
+	     * Database is fully built if build_db_exit_status == 0.
+	     */
+
+	}
+
+    }
 
+    /**
+     * Else dbopen was bunk -- return exit status.
+     */
 
+    return build_db_exit_status;
+
 }
 
+/**
+ * @brief Cache recent entry into file database, substituting the
+ * current entry for the least recently cached one.
+ * @return 0 on success
+ * @return 1 on failure
+ */
 int
 cache_file_entry(DB *database, const void *entry, const size_t entry_size)
 {
 
+    int cache_exit_status;
 
+    
+
+    remove_lru_cache_entry(database, entry_size);
 
+    return cache_exit_status;
 
 }
 
+/**
+ * @brief Cache recent entry into pkg database, substituting
+ * the current entry for the least recently cached one.
+ * @return 0 on success
+ * @return 1 on failure
+ */
 int
 cache_pkg_entry(DB *database, const void *entry, const size_t entry_size)
 {
 
+    int cache_exit_status;
+
+    
 
+    remove_lru_cache_entry(database, entry_size);
 
+    return cache_exit_status;
 
 }
 
+/**
+ * @brief Remove least recently used cache entry to make room
+ * for another entry (the most recently used entry). 
+ * @return -1 on no change
+ * @return 0 on success
+ * @return 1 on failure
+ */
 int
-flush_changes(DB *database, const void *entry_list, const size_t entry_size)
+remove_lru_cache_entry(DB *database, const size_t entry_size)
+{
+
+    DBT
+	/**
+	 * Cache updating related items.
+	 *
+	 * - cache_retrieved is the initial information.
+	 * - cache_displaced is the information which will
+	 * be copied and replace the old cache info.
+	 */
+	cache_query,
+	cache_retrieved,
+	cache_displaced,
+	/**
+	 * Header related items.
+	 *
+	 * - header_query is the query info for the
+	 * header.
+	 * - header_retrieved is the returned header from
+	 * the database
+	 */
+	header_query = { __HEADER_TITLE, sizeof(__HEADER_TITLE) },
+	header_retrieved;
+
+    int db_exit_status = database->get(, 0);
+
+    /**
+     * Ok, there is a cache. Let's proceed.
+     */
+    if(0 == db_exit_status) {
+	
+	
+
+    }
+
+    return db_exit_status;
+
+}
+
+/**
+ * @brief Setup the database header; this should only be
+ * executed after building the database.
+ * @return 0 on success
+ * @return 1 on failure
+ */
+int
+initialize_database_header(DB *database)
+{
+
+    
+
+}
+
+/**
+ * @brief Setup the entry cache; this should only be executed
+ * after building the database.
+ * @return 0 on success
+ * @return 1 on failure
+ */
+int
+initialize_entry_cache(DB *database)
+{
+
+    
+
+}
+
+/**
+ * @brief Cache recent entry into pkg database.
+ * @return 0 on success
+ * @return 1 on failure
+ */
+int
+flush_changes(DB *database, const void **entry_list, const size_t entry_size)
 {
 
 
@@ -44,20 +231,114 @@
 
 }
 
+/**
+ * @brief Search for file in file database.
+ * @return file_entry if found.
+ * @return NULL if not found.
+ */
 void*
 file_search(DB *database, const char *key)
 {
 
+    file_entry *entry;
 
+    db_search(entry, sizeof(file_entry), DB, key);
 
+    return entry;
 
 }
 
+/**
+ * @brief Search for package in pkg database.
+ * @return the pkg_entry if found.
+ * @return NULL if not found.
+ */
 void*
 pkg_search(DB *database, const char *key)
 {
 
+    pkg_entry *entry;
+
+    db_search(entry, sizeof(pkg_entry), DB, key);
 
+    return entry;
+
+}
 
+/**
+ * @brief Generic search method through a database, common
+ * to both searching the file and pkg databases.
+ * @return 1 on successful find
+ * @return 0 on successful find.
+ * @return 1 on lack of resources (memset / malloc failed)
+ * or unknown BDB failure (check errno?)
+ *
+ */
+
+/**
+ * Should the entries be globbable/pattern searchable? If
+ * so, then there would be more entires that would need to
+ * be returned than just 1.
+ */
+int
+db_search(void *found_entry, const size_t found_entry_size, DB *database, const char *key)
+{
+
+    DBT search_key = { key, sizeof(key) };
+    DBT db_found_entry = calloc(1, sizeof(DBT));
+
+    int exit_status;
+
+    /**
+     * The search subroutine.
+     */
+    int db_get_exit_status = database->get(database, &search_key, &db_found_entry, 0);
+
+    /**
+     * Success! We found it and everything passed in
+     * creating the DBT objects.
+     */
+    if(0 == db_get_exit_status) {
+
+	assert(found_entry_size == db_found_entry->size);
+
+	exit_status = 1;
+
+	/**
+	 * If the malloc was successful, continue on
+	 * with the memcpy.
+	 */
+	if( NULL != (found_entry = malloc(found_entry_size)) ) {
+
+	    /**
+	     * If the memset was successful, then the
+	     * copy was good and the retrieval was
+	     * complete.
+	     */
+	    if( NULL != (found_entry = memset(	found_entry,
+					    	db_found_entry->data,
+						db_found_entry->size))
+	    ) {
+		exit_status = 0;
+	    }
+
+	}
+
+    }
+    /**
+     * Else if the key's positive, there was an
+     * unknown BDB error.
+     */
+    else if(0 < db_get_exit_status) {
+	exit_status = 1;
+    }
+    /**
+     * Else, the key wasn't found.
+     */
+    else {
+	exit_status = -1;
+    }
+
+    return exit_status;
 
 }

==== //depot/projects/soc2007/revised_fbsd_pkgtools/v2/lib/db/api.h#2 (text+ko) ====

@@ -7,11 +7,36 @@
 #include <fcntl.h>
 #include <limits.h>
 
+#include <string.h>
+
+/**
+ * The database will appear something like this (abstractly):
+ *
+ *    __HEADER
+ *    __DATA_STORE  (keyed)
+ *    __ENTRY_CACHE (keyed)
+ *
+ * Where the __HEADER is like the following:
+ *
+ *
+ */
+
+/**
+ *
+ * The title for the cache field.
+ */
+#define __CACHE_FIELD_TITLE	"__CACHE"
+
+/**
+ * The title for the header field.
+ */
+#define __HEADER_FIELD_TITLE	"__HEADER"
+
 typedef struct {
 
     DB		bdb_obj;
 
-    int		(*build_db)	(DB*, const char*, const char*);
+    int		(*build_db)	(DB*, const char*, const char**);
     int		(*cache_entry)	(DB*, const void*, const size_t);
     int		(*flush_changes)(DB*, const void*, const size_t);
     int		(*init_db)	(DB*, const char*);
@@ -19,19 +44,27 @@
 
 } db;
 
-/** BUILD DATABASES FROM FILES **/
-int	build_filedb(DB*, const char*, const char*);
-int	build_pkgdb(DB*, const char*, const char*);
+/** Database building functions **/
+int	build_filedb(DB*, const char*, const char**);
+int	build_pkgdb(DB*, const char*, const char**);
 
-/** CACHE ENTRIES **/
+/** Cache maintenance functions **/
 int	cache_file_entry(DB*, const void* const size_t);
 int	cache_pkg_entry(DB*, const void*, const size_t);
 
-/** FLUSH CHANGES **/
+int     remove_lru_cache_entry(DB*, const size_t);
+
+/** For initializing required fields in the databases **/
+int     initialize_database_header(DB*);
+int     initialize_entry_cache(DB*);
+
+/** Functions for flushing changes **/
 int	flush_changes(DB*, const void*, const size_t);
 
-/** SEARCH **/
+/** Functions for search databases **/
 void*	file_search(DB*, const char*);
 void*	pkg_search(DB*, const char*);
 
+int     db_search(void*, const size_t, DB*, const char *);
+
 #endif