add extended data field for arbitrary package data

This adds a mechanism for package builders to add arbitrary data to
packages that is not necessarily relevant enough to the package
installation process to gain first-class support in alpm.  Currently
these fields have to be added to parsers with a "not actually used"
comment and can't be retrieved through the API.

Extended data is stored in "name=value" format in the xdata field
(%XDATA% in desc files):

xdata = pkgtype=debug

or

%XDATA%
pkgtype=debug

Signed-off-by: Andrew Gregory <andrew.gregory.8@gmail.com>

lib/libalpm/alpm.h

@@ -2291,6 +2291,13 @@ typedef enum _alpm_pkgvalidation_t {
 	ALPM_PKG_VALIDATION_SIGNATURE = (1 << 3)
 } alpm_pkgvalidation_t;
 
+typedef struct _alpm_pkg_xdata_t {
+	char *name;
+	char *value;
+} alpm_pkg_xdata_t;
+
+alpm_list_t *alpm_pkg_get_xdata(alpm_pkg_t *pkg);
+
 /** Create a package from a file.
  * If full is false, the archive is read only until all necessary
  * metadata is found. If it is true, the entire archive is read, which

lib/libalpm/be_local.c

@@ -195,6 +195,12 @@ static alpm_list_t *_cache_get_backup(alpm_pkg_t *pkg)
 	return pkg->backup;
 }
 
+static alpm_list_t *_cache_get_xdata(alpm_pkg_t *pkg)
+{
+	LAZY_LOAD(INFRQ_DESC);
+	return pkg->xdata;
+}
+
 /**
  * Open a package changelog for reading. Similar to fopen in functionality,
  * except that the returned 'file stream' is from the database.
@@ -349,6 +355,7 @@ static const struct pkg_operations local_pkg_ops = {
 	.get_replaces = _cache_get_replaces,
 	.get_files = _cache_get_files,
 	.get_backup = _cache_get_backup,
+	.get_xdata = _cache_get_xdata,
 
 	.changelog_open = _cache_changelog_open,
 	.changelog_read = _cache_changelog_read,
@@ -804,6 +811,18 @@ static int local_db_read(alpm_pkg_t *info, int inforeq)
 				READ_AND_SPLITDEP(info->conflicts);
 			} else if(strcmp(line, "%PROVIDES%") == 0) {
 				READ_AND_SPLITDEP(info->provides);
+			} else if(strcmp(line, "%XDATA%") == 0) {
+				alpm_list_t *i, *lines = NULL;
+				READ_AND_STORE_ALL(lines);
+				for(i = lines; i; i = i->next) {
+					alpm_pkg_xdata_t *pd = _alpm_pkg_parse_xdata(i->data);
+					if(pd == NULL || !alpm_list_append(&info->xdata, pd)) {
+						_alpm_pkg_xdata_free(pd);
+						FREELIST(lines);
+						goto error;
+					}
+				}
+				FREELIST(lines);
 			}
 		}
 		fclose(fp);
@@ -1040,6 +1059,15 @@ int _alpm_local_db_write(alpm_db_t *db, alpm_pkg_t *info, int inforeq)
 		write_deps(fp, "%CONFLICTS%", info->conflicts);
 		write_deps(fp, "%PROVIDES%", info->provides);
 
+		if(info->xdata) {
+			fputs("%XDATA%\n", fp);
+			for(lp = info->xdata; lp; lp = lp->next) {
+				alpm_pkg_xdata_t *pd = lp->data;
+				fprintf(fp, "%s=%s\n", pd->name, pd->value);
+			}
+			fputc('\n', fp);
+		}
+
 		fclose(fp);
 		fp = NULL;
 	}

lib/libalpm/be_package.c

@@ -246,6 +246,12 @@ static int parse_descfile(alpm_handle_t *handle, struct archive *a, alpm_pkg_t *
 				newpkg->backup = alpm_list_add(newpkg->backup, backup);
 			} else if(strcmp(key, "pkgtype") == 0) {
 				/* not used atm */
+			} else if(strcmp(key, "xdata") == 0) {
+				alpm_pkg_xdata_t *pd = _alpm_pkg_parse_xdata(ptr);
+				if(pd == NULL || !alpm_list_append(&newpkg->xdata, pd)) {
+					_alpm_pkg_xdata_free(pd);
+					return -1;
+				}
 			} else {
 				_alpm_log(handle, ALPM_LOG_DEBUG, "%s: unknown key '%s' in description file line %d\n",
 									newpkg->name ? newpkg->name : "error", key, linenum);

lib/libalpm/be_sync.c

@@ -666,6 +666,18 @@ static int sync_db_read(alpm_db_t *db, struct archive *archive,
 				pkg->files.count = files_count;
 				pkg->files.files = files;
 				_alpm_filelist_sort(&pkg->files);
+			} else if(strcmp(line, "%DATA%") == 0) {
+				alpm_list_t *i, *lines = NULL;
+				READ_AND_STORE_ALL(lines);
+				for(i = lines; i; i = i->next) {
+					alpm_pkg_xdata_t *pd = _alpm_pkg_parse_xdata(i->data);
+					if(pd == NULL || !alpm_list_append(&pkg->xdata, pd)) {
+						_alpm_pkg_xdata_free(pd);
+						FREELIST(lines);
+						goto error;
+					}
+				}
+				FREELIST(lines);
 			}
 		}
 		if(ret != ARCHIVE_EOF) {

lib/libalpm/package.c

@@ -98,6 +98,7 @@ static alpm_list_t *_pkg_get_provides(alpm_pkg_t *pkg)   { return pkg->provides;
 static alpm_list_t *_pkg_get_replaces(alpm_pkg_t *pkg)   { return pkg->replaces; }
 static alpm_filelist_t *_pkg_get_files(alpm_pkg_t *pkg)  { return &(pkg->files); }
 static alpm_list_t *_pkg_get_backup(alpm_pkg_t *pkg)     { return pkg->backup; }
+static alpm_list_t *_pkg_get_xdata(alpm_pkg_t *pkg)      { return pkg->xdata; }
 
 static void *_pkg_changelog_open(alpm_pkg_t UNUSED *pkg)
 {
@@ -162,6 +163,7 @@ const struct pkg_operations default_pkg_ops = {
 	.get_replaces    = _pkg_get_replaces,
 	.get_files       = _pkg_get_files,
 	.get_backup      = _pkg_get_backup,
+	.get_xdata       = _pkg_get_xdata,
 
 	.changelog_open  = _pkg_changelog_open,
 	.changelog_read  = _pkg_changelog_read,
@@ -485,6 +487,13 @@ int SYMEXPORT alpm_pkg_has_scriptlet(alpm_pkg_t *pkg)
 	return pkg->ops->has_scriptlet(pkg);
 }
 
+alpm_list_t SYMEXPORT *alpm_pkg_get_xdata(alpm_pkg_t *pkg)
+{
+	ASSERT(pkg != NULL, return NULL);
+	pkg->handle->pm_errno = ALPM_ERR_OK;
+	return pkg->ops->get_xdata(pkg);
+}
+
 static void find_requiredby(alpm_pkg_t *pkg, alpm_db_t *db, alpm_list_t **reqs,
 		int optional)
 {
@@ -677,6 +686,30 @@ static void free_deplist(alpm_list_t *deps)
 	alpm_list_free(deps);
 }
 
+alpm_pkg_xdata_t *_alpm_pkg_parse_xdata(const char *string)
+{
+	alpm_pkg_xdata_t *pd;
+	const char *sep;
+	if(string == NULL || (sep = strchr(string, '=')) == NULL) {
+		return NULL;
+	}
+
+	CALLOC(pd, 1, sizeof(alpm_pkg_xdata_t), return NULL);
+	STRNDUP(pd->name, string, sep - string, FREE(pd); return NULL);
+	STRDUP(pd->value, sep + 1, FREE(pd->name); FREE(pd); return NULL);
+
+	return pd;
+}
+
+void _alpm_pkg_xdata_free(alpm_pkg_xdata_t *pd)
+{
+	if(pd) {
+		free(pd->name);
+		free(pd->value);
+		free(pd);
+	}
+}
+
 void _alpm_pkg_free(alpm_pkg_t *pkg)
 {
 	if(pkg == NULL) {
@@ -707,6 +740,8 @@ void _alpm_pkg_free(alpm_pkg_t *pkg)
 	}
 	alpm_list_free_inner(pkg->backup, (alpm_list_fn_free)_alpm_backup_free);
 	alpm_list_free(pkg->backup);
+	alpm_list_free_inner(pkg->xdata, (alpm_list_fn_free)_alpm_pkg_xdata_free);
+	alpm_list_free(pkg->xdata);
 	free_deplist(pkg->depends);
 	free_deplist(pkg->optdepends);
 	free_deplist(pkg->checkdepends);

lib/libalpm/package.h

@@ -67,6 +67,8 @@ struct pkg_operations {
 	alpm_filelist_t *(*get_files) (alpm_pkg_t *);
 	alpm_list_t *(*get_backup) (alpm_pkg_t *);
 
+	alpm_list_t *(*get_xdata) (alpm_pkg_t *);
+
 	void *(*changelog_open) (alpm_pkg_t *);
 	size_t (*changelog_read) (void *, size_t, const alpm_pkg_t *, void *);
 	int (*changelog_close) (const alpm_pkg_t *, void *);
@@ -136,6 +138,8 @@ struct _alpm_pkg_t {
 	alpm_pkgreason_t reason;
 	int scriptlet;
 
+	alpm_list_t *xdata;
+
 	/* Bitfield from alpm_dbinfrq_t */
 	int infolevel;
 	/* Bitfield from alpm_pkgvalidation_t */
@@ -158,4 +162,7 @@ alpm_pkg_t *_alpm_pkg_load_internal(alpm_handle_t *handle,
 int _alpm_pkg_cmp(const void *p1, const void *p2);
 int _alpm_pkg_compare_versions(alpm_pkg_t *local_pkg, alpm_pkg_t *pkg);
 
+alpm_pkg_xdata_t *_alpm_pkg_parse_xdata(const char *string);
+void _alpm_pkg_xdata_free(alpm_pkg_xdata_t *pd);
+
 #endif /* ALPM_PACKAGE_H */