5 files changed, 398 insertions, 92 deletions

diff --git a/lib/libalpm/be_files.c b/lib/libalpm/be_files.c
index c0298049..e8573947 100644
--- a/lib/libalpm/be_files.c
+++ b/lib/libalpm/be_files.c
@@ -1,8 +1,8 @@
 /*
  *  be_files.c
  *
- *  Copyright (c) 2006 by Christian Hamar <krics@linuxforum.hu>
- *  Copyright (c) 2006 by Miklos Vajna <vmiklos@frugalware.org>
+ *  Copyright (c) 2006-2010 Pacman Development Team <pacman-dev@archlinux.org>
+ *  Copyright (c) 2002-2006 by Judd Vinet <jvinet@zeroflux.org>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License as published by
@@ -51,6 +51,247 @@
 #include "dload.h"
 
 
+#define LAZY_LOAD(info, errret) \
+	do { \
+		ALPM_LOG_FUNC; \
+		ASSERT(handle != NULL, return(errret)); \
+		ASSERT(pkg != NULL, return(errret)); \
+		if(pkg->origin != PKG_FROM_FILE && !(pkg->infolevel & info)) { \
+			_alpm_db_read(pkg->origin_data.db, pkg, info); \
+		} \
+	} while(0)
+
+
+/* Cache-specific accessor functions. These implementations allow for lazy
+ * loading by the files backend when a data member is actually needed
+ * rather than loading all pieces of information when the package is first
+ * initialized.
+ */
+
+const char *_cache_get_filename(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->filename;
+}
+
+const char *_cache_get_name(pmpkg_t *pkg)
+{
+	ASSERT(pkg != NULL, return(NULL));
+	return pkg->name;
+}
+
+static const char *_cache_get_version(pmpkg_t *pkg)
+{
+	ASSERT(pkg != NULL, return(NULL));
+	return pkg->version;
+}
+
+static const char *_cache_get_desc(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->desc;
+}
+
+const char *_cache_get_url(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->url;
+}
+
+time_t _cache_get_builddate(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, 0);
+	return pkg->builddate;
+}
+
+time_t _cache_get_installdate(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, 0);
+	return pkg->installdate;
+}
+
+const char *_cache_get_packager(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->packager;
+}
+
+const char *_cache_get_md5sum(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->md5sum;
+}
+
+const char *_cache_get_arch(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->arch;
+}
+
+off_t _cache_get_size(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, -1);
+	return pkg->size;
+}
+
+off_t _cache_get_isize(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, -1);
+	return pkg->isize;
+}
+
+pmpkgreason_t _cache_get_reason(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, -1);
+	return pkg->reason;
+}
+
+alpm_list_t *_cache_get_licenses(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->licenses;
+}
+
+alpm_list_t *_cache_get_groups(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->groups;
+}
+
+int _cache_has_force(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, -1);
+	return pkg->force;
+}
+
+alpm_list_t *_cache_get_depends(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DEPENDS, NULL);
+	return pkg->depends;
+}
+
+alpm_list_t *_cache_get_optdepends(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DEPENDS, NULL);
+	return pkg->optdepends;
+}
+
+alpm_list_t *_cache_get_conflicts(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DEPENDS, NULL);
+	return pkg->conflicts;
+}
+
+alpm_list_t *_cache_get_provides(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DEPENDS, NULL);
+	return pkg->provides;
+}
+
+alpm_list_t *_cache_get_replaces(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC, NULL);
+	return pkg->replaces;
+}
+
+alpm_list_t *_cache_get_deltas(pmpkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DELTAS, NULL);
+	return pkg->deltas;
+}
+
+alpm_list_t *_cache_get_files(pmpkg_t *pkg)
+{
+	ALPM_LOG_FUNC;
+
+	/* Sanity checks */
+	ASSERT(handle != NULL, return(NULL));
+	ASSERT(pkg != NULL, return(NULL));
+
+	if(pkg->origin == PKG_FROM_LOCALDB
+		 && !(pkg->infolevel & INFRQ_FILES)) {
+		_alpm_db_read(pkg->origin_data.db, pkg, INFRQ_FILES);
+	}
+	return pkg->files;
+}
+
+alpm_list_t *_cache_get_backup(pmpkg_t *pkg)
+{
+	ALPM_LOG_FUNC;
+
+	/* Sanity checks */
+	ASSERT(handle != NULL, return(NULL));
+	ASSERT(pkg != NULL, return(NULL));
+
+	if(pkg->origin == PKG_FROM_LOCALDB
+		 && !(pkg->infolevel & INFRQ_FILES)) {
+		_alpm_db_read(pkg->origin_data.db, pkg, INFRQ_FILES);
+	}
+	return pkg->backup;
+}
+
+/** The sync database operations struct. Get package fields through
+ * lazy accessor methods that handle any backend loading and caching
+ * logic.
+ */
+static struct pkg_operations sync_pkg_ops = {
+	.get_filename    = _cache_get_filename,
+	.get_name        = _cache_get_name,
+	.get_version     = _cache_get_version,
+	.get_desc        = _cache_get_desc,
+	.get_url         = _cache_get_url,
+	.get_builddate   = _cache_get_builddate,
+	.get_installdate = _cache_get_installdate,
+	.get_packager    = _cache_get_packager,
+	.get_md5sum      = _cache_get_md5sum,
+	.get_arch        = _cache_get_arch,
+	.get_size        = _cache_get_size,
+	.get_isize       = _cache_get_isize,
+	.get_reason      = _cache_get_reason,
+	.has_force       = _cache_has_force,
+	.get_licenses    = _cache_get_licenses,
+	.get_groups      = _cache_get_groups,
+	.get_depends     = _cache_get_depends,
+	.get_optdepends  = _cache_get_optdepends,
+	.get_conflicts   = _cache_get_conflicts,
+	.get_provides    = _cache_get_provides,
+	.get_replaces    = _cache_get_replaces,
+	.get_deltas      = _cache_get_deltas,
+	.get_files       = _cache_get_files,
+	.get_backup      = _cache_get_backup,
+};
+
+/** The local database operations struct. Get package fields through
+ * lazy accessor methods that handle any backend loading and caching
+ * logic.
+ */
+static struct pkg_operations local_pkg_ops = {
+	.get_filename    = _cache_get_filename,
+	.get_name        = _cache_get_name,
+	.get_version     = _cache_get_version,
+	.get_desc        = _cache_get_desc,
+	.get_url         = _cache_get_url,
+	.get_builddate   = _cache_get_builddate,
+	.get_installdate = _cache_get_installdate,
+	.get_packager    = _cache_get_packager,
+	.get_md5sum      = _cache_get_md5sum,
+	.get_arch        = _cache_get_arch,
+	.get_size        = _cache_get_size,
+	.get_isize       = _cache_get_isize,
+	.get_reason      = _cache_get_reason,
+	.has_force       = _cache_has_force,
+	.get_licenses    = _cache_get_licenses,
+	.get_groups      = _cache_get_groups,
+	.get_depends     = _cache_get_depends,
+	.get_optdepends  = _cache_get_optdepends,
+	.get_conflicts   = _cache_get_conflicts,
+	.get_provides    = _cache_get_provides,
+	.get_replaces    = _cache_get_replaces,
+	.get_deltas      = _cache_get_deltas,
+	.get_files       = _cache_get_files,
+	.get_backup      = _cache_get_backup,
+};
+
 static int checkdbdir(pmdb_t *db)
 {
 	struct stat buf;
@@ -417,8 +658,10 @@ int _alpm_db_populate(pmdb_t *db)
 		}
 		if(db == handle->db_local) {
 			pkg->origin = PKG_FROM_LOCALDB;
+			pkg->ops = &local_pkg_ops;
 		}  else {
 			pkg->origin = PKG_FROM_SYNCDB;
+			pkg->ops = &sync_pkg_ops;
 		}
 		pkg->origin_data.db = db;
 		/* add to the collection */
diff --git a/lib/libalpm/be_package.c b/lib/libalpm/be_package.c
index 3d8c4e38..f581813c 100644
--- a/lib/libalpm/be_package.c
+++ b/lib/libalpm/be_package.c
@@ -234,7 +234,9 @@ static pmpkg_t *pkg_load(const char *pkgfile, int full)
 
 	/* internal fields for package struct */
 	newpkg->origin = PKG_FROM_FILE;
+	/* TODO eventually kill/move this? */
 	newpkg->origin_data.file = strdup(pkgfile);
+	newpkg->ops = &default_pkg_ops;
 
 	if(full) {
 		/* "checking for conflicts" requires a sorted list, ensure that here */
diff --git a/lib/libalpm/cache.c b/lib/libalpm/cache.c
index 5126f3b1..096f59d0 100644
--- a/lib/libalpm/cache.c
+++ b/lib/libalpm/cache.c
@@ -98,7 +98,7 @@ alpm_list_t *_alpm_db_get_pkgcache(pmdb_t *db)
 	return(db->pkgcache);
 }
 
-/* "duplicate" pkg with BASE info (to spare some memory) then add it to pkgcache */
+/* "duplicate" pkg then add it to pkgcache */
 int _alpm_db_add_pkgincache(pmdb_t *db, pmpkg_t *pkg)
 {
 	pmpkg_t *newpkg;
@@ -109,17 +109,10 @@ int _alpm_db_add_pkgincache(pmdb_t *db, pmpkg_t *pkg)
 		return(-1);
 	}
 
-	newpkg = _alpm_pkg_new();
+	newpkg = _alpm_pkg_dup(pkg);
 	if(newpkg == NULL) {
 		return(-1);
 	}
-	newpkg->name = strdup(pkg->name);
-	newpkg->version = strdup(pkg->version);
-	if(newpkg->name == NULL || newpkg->version == NULL) {
-		pm_errno = PM_ERR_MEMORY;
-		_alpm_pkg_free(newpkg);
-		return(-1);
-	}
 
 	_alpm_log(PM_LOG_DEBUG, "adding entry '%s' in '%s' cache\n",
 						alpm_pkg_get_name(newpkg), db->treename);
diff --git a/lib/libalpm/package.c b/lib/libalpm/package.c
index d30e6138..4f7cc2db 100644
--- a/lib/libalpm/package.c
+++ b/lib/libalpm/package.c
@@ -99,176 +99,187 @@ int SYMEXPORT alpm_pkg_checkmd5sum(pmpkg_t *pkg)
 	return(retval);
 }
 
-#define LAZY_LOAD(info, errret) \
-	do { \
-	ALPM_LOG_FUNC; \
-	ASSERT(handle != NULL, return(errret)); \
-	ASSERT(pkg != NULL, return(errret)); \
-	if(pkg->origin != PKG_FROM_FILE && !(pkg->infolevel & info)) { \
-		_alpm_db_read(pkg->origin_data.db, pkg, info); \
-	} \
-	} while(0)
-
+/* Default package accessor functions. These will get overridden by any
+ * backend logic that needs lazy access, such as the local database through
+ * a lazy-laod cache. However, the defaults will work just fine for fully-
+ * populated package structures. */
+const char *_pkg_get_filename(pmpkg_t *pkg)    { return pkg->filename; }
+const char *_pkg_get_name(pmpkg_t *pkg)        { return pkg->name; }
+const char *_pkg_get_version(pmpkg_t *pkg)     { return pkg->version; }
+const char *_pkg_get_desc(pmpkg_t *pkg)        { return pkg->desc; }
+const char *_pkg_get_url(pmpkg_t *pkg)         { return pkg->url; }
+time_t _pkg_get_builddate(pmpkg_t *pkg)        { return pkg->builddate; }
+time_t _pkg_get_installdate(pmpkg_t *pkg)      { return pkg->installdate; }
+const char *_pkg_get_packager(pmpkg_t *pkg)    { return pkg->packager; }
+const char *_pkg_get_md5sum(pmpkg_t *pkg)      { return pkg->md5sum; }
+const char *_pkg_get_arch(pmpkg_t *pkg)        { return pkg->arch; }
+off_t _pkg_get_size(pmpkg_t *pkg)              { return pkg->size; }
+off_t _pkg_get_isize(pmpkg_t *pkg)             { return pkg->isize; }
+pmpkgreason_t _pkg_get_reason(pmpkg_t *pkg)    { return pkg->reason; }
+int _pkg_has_force(pmpkg_t *pkg)               { return pkg->force; }
+
+alpm_list_t *_pkg_get_licenses(pmpkg_t *pkg)   { return pkg->licenses; }
+alpm_list_t *_pkg_get_groups(pmpkg_t *pkg)     { return pkg->groups; }
+alpm_list_t *_pkg_get_depends(pmpkg_t *pkg)    { return pkg->depends; }
+alpm_list_t *_pkg_get_optdepends(pmpkg_t *pkg) { return pkg->optdepends; }
+alpm_list_t *_pkg_get_conflicts(pmpkg_t *pkg)  { return pkg->conflicts; }
+alpm_list_t *_pkg_get_provides(pmpkg_t *pkg)   { return pkg->provides; }
+alpm_list_t *_pkg_get_replaces(pmpkg_t *pkg)   { return pkg->replaces; }
+alpm_list_t *_pkg_get_deltas(pmpkg_t *pkg)     { return pkg->deltas; }
+alpm_list_t *_pkg_get_files(pmpkg_t *pkg)      { return pkg->files; }
+alpm_list_t *_pkg_get_backup(pmpkg_t *pkg)     { return pkg->backup; }
+
+/** The standard package operations struct. Get fields directly from the
+ * struct itself with no abstraction layer or any type of lazy loading.
+ */
+struct pkg_operations default_pkg_ops = {
+	.get_filename    = _pkg_get_filename,
+	.get_name        = _pkg_get_name,
+	.get_version     = _pkg_get_version,
+	.get_desc        = _pkg_get_desc,
+	.get_url         = _pkg_get_url,
+	.get_builddate   = _pkg_get_builddate,
+	.get_installdate = _pkg_get_installdate,
+	.get_packager    = _pkg_get_packager,
+	.get_md5sum      = _pkg_get_md5sum,
+	.get_arch        = _pkg_get_arch,
+	.get_size        = _pkg_get_size,
+	.get_isize       = _pkg_get_isize,
+	.get_reason      = _pkg_get_reason,
+	.has_force       = _pkg_has_force,
+	.get_licenses    = _pkg_get_licenses,
+	.get_groups      = _pkg_get_groups,
+	.get_depends     = _pkg_get_depends,
+	.get_optdepends  = _pkg_get_optdepends,
+	.get_conflicts   = _pkg_get_conflicts,
+	.get_provides    = _pkg_get_provides,
+	.get_replaces    = _pkg_get_replaces,
+	.get_deltas      = _pkg_get_deltas,
+	.get_files       = _pkg_get_files,
+	.get_backup      = _pkg_get_backup,
+};
+
+/* Public functions for getting package information. These functions
+ * delegate the hard work to the function callbacks attached to each
+ * package, which depend on where the package was loaded from. */
 const char SYMEXPORT *alpm_pkg_get_filename(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->filename;
+	return pkg->ops->get_filename(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_name(pmpkg_t *pkg)
 {
-	ASSERT(pkg != NULL, return(NULL));
-	return pkg->name;
+	return pkg->ops->get_name(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_version(pmpkg_t *pkg)
 {
-	ASSERT(pkg != NULL, return(NULL));
-	return pkg->version;
+	return pkg->ops->get_version(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_desc(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->desc;
+	return pkg->ops->get_desc(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_url(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->url;
+	return pkg->ops->get_url(pkg);
 }
 
 time_t SYMEXPORT alpm_pkg_get_builddate(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, 0);
-	return pkg->builddate;
+	return pkg->ops->get_builddate(pkg);
 }
 
 time_t SYMEXPORT alpm_pkg_get_installdate(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, 0);
-	return pkg->installdate;
+	return pkg->ops->get_installdate(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_packager(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->packager;
+	return pkg->ops->get_packager(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_md5sum(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->md5sum;
+	return pkg->ops->get_md5sum(pkg);
 }
 
 const char SYMEXPORT *alpm_pkg_get_arch(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->arch;
+	return pkg->ops->get_arch(pkg);
 }
 
 off_t SYMEXPORT alpm_pkg_get_size(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, -1);
-	return pkg->size;
+	return pkg->ops->get_size(pkg);
 }
 
 off_t SYMEXPORT alpm_pkg_get_isize(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, -1);
-	return pkg->isize;
+	return pkg->ops->get_isize(pkg);
 }
 
 pmpkgreason_t SYMEXPORT alpm_pkg_get_reason(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, -1);
-	return pkg->reason;
+	return pkg->ops->get_reason(pkg);
 }
 
-alpm_list_t SYMEXPORT *alpm_pkg_get_licenses(pmpkg_t *pkg)
+int SYMEXPORT alpm_pkg_has_force(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->licenses;
+	return pkg->ops->has_force(pkg);
 }
 
-alpm_list_t SYMEXPORT *alpm_pkg_get_groups(pmpkg_t *pkg)
+alpm_list_t SYMEXPORT *alpm_pkg_get_licenses(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->groups;
+	return pkg->ops->get_licenses(pkg);
 }
 
-int SYMEXPORT alpm_pkg_has_force(pmpkg_t *pkg)
+alpm_list_t SYMEXPORT *alpm_pkg_get_groups(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, -1);
-	return pkg->force;
+	return pkg->ops->get_groups(pkg);
 }
 
 alpm_list_t SYMEXPORT *alpm_pkg_get_depends(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DEPENDS, NULL);
-	return pkg->depends;
+	return pkg->ops->get_depends(pkg);
 }
 
 alpm_list_t SYMEXPORT *alpm_pkg_get_optdepends(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DEPENDS, NULL);
-	return pkg->optdepends;
+	return pkg->ops->get_optdepends(pkg);
 }
 
 alpm_list_t SYMEXPORT *alpm_pkg_get_conflicts(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DEPENDS, NULL);
-	return pkg->conflicts;
+	return pkg->ops->get_conflicts(pkg);
 }
 
 alpm_list_t SYMEXPORT *alpm_pkg_get_provides(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DEPENDS, NULL);
-	return pkg->provides;
+	return pkg->ops->get_provides(pkg);
 }
 
-alpm_list_t SYMEXPORT *alpm_pkg_get_deltas(pmpkg_t *pkg)
+alpm_list_t SYMEXPORT *alpm_pkg_get_replaces(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DELTAS, NULL);
-	return pkg->deltas;
+	return pkg->ops->get_replaces(pkg);
 }
 
-alpm_list_t SYMEXPORT *alpm_pkg_get_replaces(pmpkg_t *pkg)
+alpm_list_t SYMEXPORT *alpm_pkg_get_deltas(pmpkg_t *pkg)
 {
-	LAZY_LOAD(INFRQ_DESC, NULL);
-	return pkg->replaces;
+	return pkg->ops->get_deltas(pkg);
 }
 
 alpm_list_t SYMEXPORT *alpm_pkg_get_files(pmpkg_t *pkg)
 {
-	ALPM_LOG_FUNC;
-
-	/* Sanity checks */
-	ASSERT(handle != NULL, return(NULL));
-	ASSERT(pkg != NULL, return(NULL));
-
-	if(pkg->origin == PKG_FROM_LOCALDB
-		 && !(pkg->infolevel & INFRQ_FILES)) {
-		_alpm_db_read(pkg->origin_data.db, pkg, INFRQ_FILES);
-	}
-	return pkg->files;
+	return pkg->ops->get_files(pkg);
 }
 
 alpm_list_t SYMEXPORT *alpm_pkg_get_backup(pmpkg_t *pkg)
 {
-	ALPM_LOG_FUNC;
-
-	/* Sanity checks */
-	ASSERT(handle != NULL, return(NULL));
-	ASSERT(pkg != NULL, return(NULL));
-
-	if(pkg->origin == PKG_FROM_LOCALDB
-		 && !(pkg->infolevel & INFRQ_FILES)) {
-		_alpm_db_read(pkg->origin_data.db, pkg, INFRQ_FILES);
-	}
-	return pkg->backup;
+	return pkg->ops->get_backup(pkg);
 }
 
 pmdb_t SYMEXPORT *alpm_pkg_get_db(pmpkg_t *pkg)
@@ -517,6 +528,7 @@ pmpkg_t *_alpm_pkg_dup(pmpkg_t *pkg)
 
 	/* internal */
 	newpkg->origin = pkg->origin;
+	newpkg->ops = pkg->ops;
 	if(newpkg->origin == PKG_FROM_FILE) {
 		newpkg->origin_data.file = strdup(pkg->origin_data.file);
 	} else {
diff --git a/lib/libalpm/package.h b/lib/libalpm/package.h
index daff9717..5ad553ac 100644
--- a/lib/libalpm/package.h
+++ b/lib/libalpm/package.h
@@ -36,6 +36,60 @@ typedef enum _pmpkgfrom_t {
 	PKG_FROM_SYNCDB
 } pmpkgfrom_t;
 
+/** Package operations struct. This struct contains function pointers to
+ * all methods used to access data in a package to allow for things such
+ * as lazy package intialization (such as used by the file backend). Each
+ * backend is free to define a stuct containing pointers to a specific
+ * implementation of these methods. Some backends may find using the
+ * defined default_pkg_ops struct to work just fine for their needs.
+ */
+struct pkg_operations {
+	const char *(*get_filename) (pmpkg_t *);
+	const char *(*get_name) (pmpkg_t *);
+	const char *(*get_version) (pmpkg_t *);
+	const char *(*get_desc) (pmpkg_t *);
+	const char *(*get_url) (pmpkg_t *);
+	time_t (*get_builddate) (pmpkg_t *);
+	time_t (*get_installdate) (pmpkg_t *);
+	const char *(*get_packager) (pmpkg_t *);
+	const char *(*get_md5sum) (pmpkg_t *);
+	const char *(*get_arch) (pmpkg_t *);
+	off_t (*get_size) (pmpkg_t *);
+	off_t (*get_isize) (pmpkg_t *);
+	pmpkgreason_t (*get_reason) (pmpkg_t *);
+	int (*has_force) (pmpkg_t *);
+
+	alpm_list_t *(*get_licenses) (pmpkg_t *);
+	alpm_list_t *(*get_groups) (pmpkg_t *);
+	alpm_list_t *(*get_depends) (pmpkg_t *);
+	alpm_list_t *(*get_optdepends) (pmpkg_t *);
+	alpm_list_t *(*get_conflicts) (pmpkg_t *);
+	alpm_list_t *(*get_provides) (pmpkg_t *);
+	alpm_list_t *(*get_replaces) (pmpkg_t *);
+	alpm_list_t *(*get_deltas) (pmpkg_t *);
+	alpm_list_t *(*get_files) (pmpkg_t *);
+	alpm_list_t *(*get_backup) (pmpkg_t *);
+
+	void *(*changelog_open) (pmpkg_t *);
+	size_t (*changelog_read) (void *, size_t, const pmpkg_t *, const void *);
+	int (*changelog_close) (const pmpkg_t *, void *);
+
+	/* still to add:
+	 * free()
+	 * dup()
+	 * checkmd5sum() ?
+	 * has_scriptlet()
+	 * compute_requiredby()
+	 */
+};
+
+/** The standard package operations struct. get fields directly from the
+ * struct itself with no abstraction layer or any type of lazy loading.
+ * The actual definition is in package.c so it can have access to the
+ * default accessor functions which are defined there.
+ */
+extern struct pkg_operations default_pkg_ops;
+
 struct __pmpkg_t {
 	char *filename;
 	char *name;
@@ -76,6 +130,8 @@ struct __pmpkg_t {
 		char *file;
 	} origin_data;
 	pmdbinfrq_t infolevel;
+
+	struct pkg_operations *ops;
 };
 
 pmpkg_t* _alpm_pkg_new(void);