From: Felix Fietkau <nbd@openwrt.org>
Date: Fri, 20 Aug 2010 12:59:27 +0000 (+0200)
Subject: uci_history -> uci_delta
X-Git-Url: http://git.archive.openwrt.org/?p=project%2Fuci.git;a=commitdiff_plain;h=c4402a9e59721172395d9403cfbe467209bcd6ad

uci_history -> uci_delta
---

diff --git a/Makefile b/Makefile
index b00aac8..9f5b313 100644
--- a/Makefile
+++ b/Makefile
@@ -23,7 +23,7 @@ SOURCES = libuci.c file.c ucimap.c util.c
 
 all: uci libuci.$(SHLIB_EXT) uci-static ucimap-example
 
-$(eval $(call add_dep,libuci,history.c list.c uci.h uci_config.h uci_internal.h))
+$(eval $(call add_dep,libuci,delta.c list.c uci.h uci_config.h uci_internal.h))
 $(eval $(call add_dep,ucimap,uci.h uci_config.h ucimap.h))
 
 cli.o: cli.c uci.h uci_config.h
diff --git a/cli.c b/cli.c
index 7bef7a9..0e98aa7 100644
--- a/cli.c
+++ b/cli.c
@@ -224,8 +224,8 @@ static void uci_show_changes(struct uci_package *p)
 {
 	struct uci_element *e;
 
-	uci_foreach_element(&p->saved_history, e) {
-		struct uci_history *h = uci_to_history(e);
+	uci_foreach_element(&p->saved_delta, e) {
+		struct uci_delta *h = uci_to_delta(e);
 		char *prefix = "";
 		char *op = "=";
 
@@ -653,10 +653,10 @@ int main(int argc, char **argv)
 				ctx->flags &= ~UCI_FLAG_EXPORT_NAME;
 				break;
 			case 'p':
-				uci_add_history_path(ctx, optarg);
+				uci_add_delta_path(ctx, optarg);
 				break;
 			case 'P':
-				uci_add_history_path(ctx, ctx->savedir);
+				uci_add_delta_path(ctx, ctx->savedir);
 				uci_set_savedir(ctx, optarg);
 				flags |= CLI_FLAG_NOCOMMIT;
 				break;
diff --git a/delta.c b/delta.c
new file mode 100644
index 0000000..e0fa1b1
--- /dev/null
+++ b/delta.c
@@ -0,0 +1,483 @@
+/*
+ * libuci - Library for the Unified Configuration Interface
+ * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1
+ * as published by the Free Software Foundation
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+/*
+ * This file contains the code for handling uci config delta files
+ */
+
+#define _GNU_SOURCE
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <sys/file.h>
+#include <stdbool.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <ctype.h>
+
+/* record a change that was done to a package */
+void
+uci_add_delta(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value)
+{
+	struct uci_delta *h;
+	int size = strlen(section) + 1;
+	char *ptr;
+
+	if (value)
+		size += strlen(value) + 1;
+
+	h = uci_alloc_element(ctx, delta, option, size);
+	ptr = uci_dataptr(h);
+	h->cmd = cmd;
+	h->section = strcpy(ptr, section);
+	if (value) {
+		ptr += strlen(ptr) + 1;
+		h->value = strcpy(ptr, value);
+	}
+	uci_list_add(list, &h->e.list);
+}
+
+void
+uci_free_delta(struct uci_delta *h)
+{
+	if (!h)
+		return;
+	if ((h->section != NULL) &&
+		(h->section != uci_dataptr(h))) {
+		free(h->section);
+		free(h->value);
+	}
+	uci_free_element(&h->e);
+}
+
+
+int uci_set_savedir(struct uci_context *ctx, const char *dir)
+{
+	char *sdir;
+
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, dir != NULL);
+
+	sdir = uci_strdup(ctx, dir);
+	if (ctx->savedir != uci_savedir)
+		free(ctx->savedir);
+	ctx->savedir = sdir;
+	return 0;
+}
+
+int uci_add_delta_path(struct uci_context *ctx, const char *dir)
+{
+	struct uci_element *e;
+
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, dir != NULL);
+	e = uci_alloc_generic(ctx, UCI_TYPE_PATH, dir, sizeof(struct uci_element));
+	uci_list_add(&ctx->delta_path, &e->list);
+
+	return 0;
+}
+
+static inline int uci_parse_delta_tuple(struct uci_context *ctx, char **buf, struct uci_ptr *ptr)
+{
+	int c = UCI_CMD_CHANGE;
+
+	switch(**buf) {
+	case '^':
+		c = UCI_CMD_REORDER;
+		break;
+	case '-':
+		c = UCI_CMD_REMOVE;
+		break;
+	case '@':
+		c = UCI_CMD_RENAME;
+		break;
+	case '+':
+		/* UCI_CMD_ADD is used for anonymous sections or list values */
+		c = UCI_CMD_ADD;
+		break;
+	case '|':
+		c = UCI_CMD_LIST_ADD;
+		break;
+	}
+
+	if (c != UCI_CMD_CHANGE)
+		*buf += 1;
+
+	UCI_INTERNAL(uci_parse_ptr, ctx, ptr, *buf);
+
+	if (!ptr->section)
+		goto error;
+	if (ptr->flags & UCI_LOOKUP_EXTENDED)
+		goto error;
+
+	switch(c) {
+	case UCI_CMD_REORDER:
+		if (!ptr->value || ptr->option)
+			goto error;
+		break;
+	case UCI_CMD_RENAME:
+		if (!ptr->value || !uci_validate_name(ptr->value))
+			goto error;
+		break;
+	case UCI_CMD_LIST_ADD:
+		if (!ptr->option)
+			goto error;
+	}
+
+	return c;
+
+error:
+	UCI_THROW(ctx, UCI_ERR_INVAL);
+	return 0;
+}
+
+static void uci_parse_delta_line(struct uci_context *ctx, struct uci_package *p, char *buf)
+{
+	struct uci_element *e = NULL;
+	struct uci_ptr ptr;
+	int cmd;
+
+	cmd = uci_parse_delta_tuple(ctx, &buf, &ptr);
+	if (strcmp(ptr.package, p->e.name) != 0)
+		goto error;
+
+	if (ctx->flags & UCI_FLAG_SAVED_DELTA)
+		uci_add_delta(ctx, &p->saved_delta, cmd, ptr.section, ptr.option, ptr.value);
+
+	switch(cmd) {
+	case UCI_CMD_REORDER:
+		expand_ptr(ctx, &ptr, true);
+		if (!ptr.s)
+			UCI_THROW(ctx, UCI_ERR_NOTFOUND);
+		UCI_INTERNAL(uci_reorder_section, ctx, ptr.s, strtoul(ptr.value, NULL, 10));
+		break;
+	case UCI_CMD_RENAME:
+		UCI_INTERNAL(uci_rename, ctx, &ptr);
+		break;
+	case UCI_CMD_REMOVE:
+		UCI_INTERNAL(uci_delete, ctx, &ptr);
+		break;
+	case UCI_CMD_LIST_ADD:
+		UCI_INTERNAL(uci_add_list, ctx, &ptr);
+		break;
+	case UCI_CMD_ADD:
+	case UCI_CMD_CHANGE:
+		UCI_INTERNAL(uci_set, ctx, &ptr);
+		e = ptr.last;
+		if (!ptr.option && e && (cmd == UCI_CMD_ADD))
+			uci_to_section(e)->anonymous = true;
+		break;
+	}
+	return;
+error:
+	UCI_THROW(ctx, UCI_ERR_PARSE);
+}
+
+/* returns the number of changes that were successfully parsed */
+static int uci_parse_delta(struct uci_context *ctx, FILE *stream, struct uci_package *p)
+{
+	struct uci_parse_context *pctx;
+	int changes = 0;
+
+	/* make sure no memory from previous parse attempts is leaked */
+	uci_cleanup(ctx);
+
+	pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
+	ctx->pctx = pctx;
+	pctx->file = stream;
+
+	while (!feof(pctx->file)) {
+		uci_getln(ctx, 0);
+		if (!pctx->buf[0])
+			continue;
+
+		/*
+		 * ignore parse errors in single lines, we want to preserve as much
+		 * delta as possible
+		 */
+		UCI_TRAP_SAVE(ctx, error);
+		uci_parse_delta_line(ctx, p, pctx->buf);
+		UCI_TRAP_RESTORE(ctx);
+		changes++;
+error:
+		continue;
+	}
+
+	/* no error happened, we can get rid of the parser context now */
+	uci_cleanup(ctx);
+	return changes;
+}
+
+/* returns the number of changes that were successfully parsed */
+static int uci_load_delta_file(struct uci_context *ctx, struct uci_package *p, char *filename, FILE **f, bool flush)
+{
+	FILE *stream = NULL;
+	int changes = 0;
+
+	UCI_TRAP_SAVE(ctx, done);
+	stream = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
+	if (p)
+		changes = uci_parse_delta(ctx, stream, p);
+	UCI_TRAP_RESTORE(ctx);
+done:
+	if (f)
+		*f = stream;
+	else if (stream)
+		uci_close_stream(stream);
+	return changes;
+}
+
+/* returns the number of changes that were successfully parsed */
+__private int uci_load_delta(struct uci_context *ctx, struct uci_package *p, bool flush)
+{
+	struct uci_element *e;
+	char *filename = NULL;
+	FILE *f = NULL;
+	int changes = 0;
+
+	if (!p->has_delta)
+		return 0;
+
+	uci_foreach_element(&ctx->delta_path, e) {
+		if ((asprintf(&filename, "%s/%s", e->name, p->e.name) < 0) || !filename)
+			UCI_THROW(ctx, UCI_ERR_MEM);
+
+		uci_load_delta_file(ctx, p, filename, NULL, false);
+		free(filename);
+	}
+
+	if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
+		UCI_THROW(ctx, UCI_ERR_MEM);
+
+	changes = uci_load_delta_file(ctx, p, filename, &f, flush);
+	if (flush && f && (changes > 0)) {
+		rewind(f);
+		if (ftruncate(fileno(f), 0) < 0) {
+			uci_close_stream(f);
+			UCI_THROW(ctx, UCI_ERR_IO);
+		}
+	}
+	if (filename)
+		free(filename);
+	uci_close_stream(f);
+	ctx->err = 0;
+	return changes;
+}
+
+static void uci_filter_delta(struct uci_context *ctx, const char *name, const char *section, const char *option)
+{
+	struct uci_parse_context *pctx;
+	struct uci_element *e, *tmp;
+	struct uci_list list;
+	char *filename = NULL;
+	struct uci_ptr ptr;
+	FILE *f = NULL;
+
+	uci_list_init(&list);
+	uci_alloc_parse_context(ctx);
+	pctx = ctx->pctx;
+
+	if ((asprintf(&filename, "%s/%s", ctx->savedir, name) < 0) || !filename)
+		UCI_THROW(ctx, UCI_ERR_MEM);
+
+	UCI_TRAP_SAVE(ctx, done);
+	f = uci_open_stream(ctx, filename, SEEK_SET, true, false);
+	pctx->file = f;
+	while (!feof(f)) {
+		struct uci_element *e;
+		char *buf;
+
+		uci_getln(ctx, 0);
+		buf = pctx->buf;
+		if (!buf[0])
+			continue;
+
+		/* NB: need to allocate the element before the call to 
+		 * uci_parse_delta_tuple, otherwise the original string 
+		 * gets modified before it is saved */
+		e = uci_alloc_generic(ctx, UCI_TYPE_DELTA, pctx->buf, sizeof(struct uci_element));
+		uci_list_add(&list, &e->list);
+
+		uci_parse_delta_tuple(ctx, &buf, &ptr);
+		if (section) {
+			if (!ptr.section || (strcmp(section, ptr.section) != 0))
+				continue;
+		}
+		if (option) {
+			if (!ptr.option || (strcmp(option, ptr.option) != 0))
+				continue;
+		}
+		/* match, drop this element again */
+		uci_free_element(e);
+	}
+
+	/* rebuild the delta file */
+	rewind(f);
+	if (ftruncate(fileno(f), 0) < 0)
+		UCI_THROW(ctx, UCI_ERR_IO);
+	uci_foreach_element_safe(&list, tmp, e) {
+		fprintf(f, "%s\n", e->name);
+		uci_free_element(e);
+	}
+	UCI_TRAP_RESTORE(ctx);
+
+done:
+	if (filename)
+		free(filename);
+	uci_close_stream(pctx->file);
+	uci_foreach_element_safe(&list, tmp, e) {
+		uci_free_element(e);
+	}
+	uci_cleanup(ctx);
+}
+
+int uci_revert(struct uci_context *ctx, struct uci_ptr *ptr)
+{
+	char *package = NULL;
+	char *section = NULL;
+	char *option = NULL;
+
+	UCI_HANDLE_ERR(ctx);
+	expand_ptr(ctx, ptr, false);
+	UCI_ASSERT(ctx, ptr->p->has_delta);
+
+	/* 
+	 * - flush unwritten changes
+	 * - save the package name
+	 * - unload the package
+	 * - filter the delta
+	 * - reload the package
+	 */
+	UCI_TRAP_SAVE(ctx, error);
+	UCI_INTERNAL(uci_save, ctx, ptr->p);
+
+	/* NB: need to clone package, section and option names, 
+	 * as they may get freed on uci_free_package() */
+	package = uci_strdup(ctx, ptr->p->e.name);
+	if (ptr->section)
+		section = uci_strdup(ctx, ptr->section);
+	if (ptr->option)
+		option = uci_strdup(ctx, ptr->option);
+
+	uci_free_package(&ptr->p);
+	uci_filter_delta(ctx, package, section, option);
+
+	UCI_INTERNAL(uci_load, ctx, package, &ptr->p);
+	UCI_TRAP_RESTORE(ctx);
+	ctx->err = 0;
+
+error:
+	if (package)
+		free(package);
+	if (section)
+		free(section);
+	if (option)
+		free(option);
+	if (ctx->err)
+		UCI_THROW(ctx, ctx->err);
+	return 0;
+}
+
+int uci_save(struct uci_context *ctx, struct uci_package *p)
+{
+	FILE *f = NULL;
+	char *filename = NULL;
+	struct uci_element *e, *tmp;
+	struct stat statbuf;
+
+	UCI_HANDLE_ERR(ctx);
+	UCI_ASSERT(ctx, p != NULL);
+
+	/* 
+	 * if the config file was outside of the /etc/config path,
+	 * don't save the delta to a file, update the real file
+	 * directly.
+	 * does not modify the uci_package pointer
+	 */
+	if (!p->has_delta)
+		return uci_commit(ctx, &p, false);
+
+	if (uci_list_empty(&p->delta))
+		return 0;
+
+	if (stat(ctx->savedir, &statbuf) < 0)
+		mkdir(ctx->savedir, UCI_DIRMODE);
+	else if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
+		UCI_THROW(ctx, UCI_ERR_IO);
+
+	if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
+		UCI_THROW(ctx, UCI_ERR_MEM);
+
+	uci_foreach_element(&ctx->hooks, tmp) {
+		struct uci_hook *hook = uci_to_hook(tmp);
+
+		if (!hook->ops->set)
+			continue;
+
+		uci_foreach_element(&p->delta, e) {
+			hook->ops->set(hook->ops, p, uci_to_delta(e));
+		}
+	}
+
+	ctx->err = 0;
+	UCI_TRAP_SAVE(ctx, done);
+	f = uci_open_stream(ctx, filename, SEEK_END, true, true);
+	UCI_TRAP_RESTORE(ctx);
+
+	uci_foreach_element_safe(&p->delta, tmp, e) {
+		struct uci_delta *h = uci_to_delta(e);
+		char *prefix = "";
+
+		switch(h->cmd) {
+		case UCI_CMD_REMOVE:
+			prefix = "-";
+			break;
+		case UCI_CMD_RENAME:
+			prefix = "@";
+			break;
+		case UCI_CMD_ADD:
+			prefix = "+";
+			break;
+		case UCI_CMD_REORDER:
+			prefix = "^";
+			break;
+		case UCI_CMD_LIST_ADD:
+			prefix = "|";
+			break;
+		default:
+			break;
+		}
+
+		fprintf(f, "%s%s.%s", prefix, p->e.name, h->section);
+		if (e->name)
+			fprintf(f, ".%s", e->name);
+
+		if (h->cmd == UCI_CMD_REMOVE)
+			fprintf(f, "\n");
+		else
+			fprintf(f, "=%s\n", h->value);
+		uci_free_delta(h);
+	}
+
+done:
+	uci_close_stream(f);
+	if (filename)
+		free(filename);
+	if (ctx->err)
+		UCI_THROW(ctx, ctx->err);
+
+	return 0;
+}
+
+
diff --git a/file.c b/file.c
index 33ba93c..0120505 100644
--- a/file.c
+++ b/file.c
@@ -694,14 +694,14 @@ void uci_file_commit(struct uci_context *ctx, struct uci_package **package, bool
 	/* open the config file for writing now, so that it is locked */
 	f = uci_open_stream(ctx, p->path, SEEK_SET, true, true);
 
-	/* flush unsaved changes and reload from history file */
+	/* flush unsaved changes and reload from delta file */
 	UCI_TRAP_SAVE(ctx, done);
-	if (p->has_history) {
+	if (p->has_delta) {
 		if (!overwrite) {
 			name = uci_strdup(ctx, p->e.name);
 			path = uci_strdup(ctx, p->path);
-			/* dump our own changes to the history file */
-			if (!uci_list_empty(&p->history))
+			/* dump our own changes to the delta file */
+			if (!uci_list_empty(&p->delta))
 				UCI_INTERNAL(uci_save, ctx, p);
 
 			/* 
@@ -713,15 +713,15 @@ void uci_file_commit(struct uci_context *ctx, struct uci_package **package, bool
 			UCI_INTERNAL(uci_import, ctx, f, name, &p, true);
 
 			p->path = path;
-			p->has_history = true;
+			p->has_delta = true;
 			*package = p;
 
 			/* freed together with the uci_package */
 			path = NULL;
 		}
 
-		/* flush history */
-		if (!uci_load_history(ctx, p, true))
+		/* flush delta */
+		if (!uci_load_delta(ctx, p, true))
 			goto done;
 	}
 
@@ -841,8 +841,8 @@ static struct uci_package *uci_file_load(struct uci_context *ctx, const char *na
 
 	if (package) {
 		package->path = filename;
-		package->has_history = confdir;
-		uci_load_history(ctx, package, false);
+		package->has_delta = confdir;
+		uci_load_delta(ctx, package, false);
 	}
 
 done:
diff --git a/history.c b/history.c
deleted file mode 100644
index 649ead1..0000000
--- a/history.c
+++ /dev/null
@@ -1,483 +0,0 @@
-/*
- * libuci - Library for the Unified Configuration Interface
- * Copyright (C) 2008 Felix Fietkau <nbd@openwrt.org>
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License version 2.1
- * as published by the Free Software Foundation
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- */
-
-/*
- * This file contains the code for handling uci config history files
- */
-
-#define _GNU_SOURCE
-#include <sys/types.h>
-#include <sys/stat.h>
-#include <sys/file.h>
-#include <stdbool.h>
-#include <unistd.h>
-#include <fcntl.h>
-#include <stdio.h>
-#include <ctype.h>
-
-/* record a change that was done to a package */
-void
-uci_add_history(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value)
-{
-	struct uci_history *h;
-	int size = strlen(section) + 1;
-	char *ptr;
-
-	if (value)
-		size += strlen(value) + 1;
-
-	h = uci_alloc_element(ctx, history, option, size);
-	ptr = uci_dataptr(h);
-	h->cmd = cmd;
-	h->section = strcpy(ptr, section);
-	if (value) {
-		ptr += strlen(ptr) + 1;
-		h->value = strcpy(ptr, value);
-	}
-	uci_list_add(list, &h->e.list);
-}
-
-void
-uci_free_history(struct uci_history *h)
-{
-	if (!h)
-		return;
-	if ((h->section != NULL) &&
-		(h->section != uci_dataptr(h))) {
-		free(h->section);
-		free(h->value);
-	}
-	uci_free_element(&h->e);
-}
-
-
-int uci_set_savedir(struct uci_context *ctx, const char *dir)
-{
-	char *sdir;
-
-	UCI_HANDLE_ERR(ctx);
-	UCI_ASSERT(ctx, dir != NULL);
-
-	sdir = uci_strdup(ctx, dir);
-	if (ctx->savedir != uci_savedir)
-		free(ctx->savedir);
-	ctx->savedir = sdir;
-	return 0;
-}
-
-int uci_add_history_path(struct uci_context *ctx, const char *dir)
-{
-	struct uci_element *e;
-
-	UCI_HANDLE_ERR(ctx);
-	UCI_ASSERT(ctx, dir != NULL);
-	e = uci_alloc_generic(ctx, UCI_TYPE_PATH, dir, sizeof(struct uci_element));
-	uci_list_add(&ctx->history_path, &e->list);
-
-	return 0;
-}
-
-static inline int uci_parse_history_tuple(struct uci_context *ctx, char **buf, struct uci_ptr *ptr)
-{
-	int c = UCI_CMD_CHANGE;
-
-	switch(**buf) {
-	case '^':
-		c = UCI_CMD_REORDER;
-		break;
-	case '-':
-		c = UCI_CMD_REMOVE;
-		break;
-	case '@':
-		c = UCI_CMD_RENAME;
-		break;
-	case '+':
-		/* UCI_CMD_ADD is used for anonymous sections or list values */
-		c = UCI_CMD_ADD;
-		break;
-	case '|':
-		c = UCI_CMD_LIST_ADD;
-		break;
-	}
-
-	if (c != UCI_CMD_CHANGE)
-		*buf += 1;
-
-	UCI_INTERNAL(uci_parse_ptr, ctx, ptr, *buf);
-
-	if (!ptr->section)
-		goto error;
-	if (ptr->flags & UCI_LOOKUP_EXTENDED)
-		goto error;
-
-	switch(c) {
-	case UCI_CMD_REORDER:
-		if (!ptr->value || ptr->option)
-			goto error;
-		break;
-	case UCI_CMD_RENAME:
-		if (!ptr->value || !uci_validate_name(ptr->value))
-			goto error;
-		break;
-	case UCI_CMD_LIST_ADD:
-		if (!ptr->option)
-			goto error;
-	}
-
-	return c;
-
-error:
-	UCI_THROW(ctx, UCI_ERR_INVAL);
-	return 0;
-}
-
-static void uci_parse_history_line(struct uci_context *ctx, struct uci_package *p, char *buf)
-{
-	struct uci_element *e = NULL;
-	struct uci_ptr ptr;
-	int cmd;
-
-	cmd = uci_parse_history_tuple(ctx, &buf, &ptr);
-	if (strcmp(ptr.package, p->e.name) != 0)
-		goto error;
-
-	if (ctx->flags & UCI_FLAG_SAVED_HISTORY)
-		uci_add_history(ctx, &p->saved_history, cmd, ptr.section, ptr.option, ptr.value);
-
-	switch(cmd) {
-	case UCI_CMD_REORDER:
-		expand_ptr(ctx, &ptr, true);
-		if (!ptr.s)
-			UCI_THROW(ctx, UCI_ERR_NOTFOUND);
-		UCI_INTERNAL(uci_reorder_section, ctx, ptr.s, strtoul(ptr.value, NULL, 10));
-		break;
-	case UCI_CMD_RENAME:
-		UCI_INTERNAL(uci_rename, ctx, &ptr);
-		break;
-	case UCI_CMD_REMOVE:
-		UCI_INTERNAL(uci_delete, ctx, &ptr);
-		break;
-	case UCI_CMD_LIST_ADD:
-		UCI_INTERNAL(uci_add_list, ctx, &ptr);
-		break;
-	case UCI_CMD_ADD:
-	case UCI_CMD_CHANGE:
-		UCI_INTERNAL(uci_set, ctx, &ptr);
-		e = ptr.last;
-		if (!ptr.option && e && (cmd == UCI_CMD_ADD))
-			uci_to_section(e)->anonymous = true;
-		break;
-	}
-	return;
-error:
-	UCI_THROW(ctx, UCI_ERR_PARSE);
-}
-
-/* returns the number of changes that were successfully parsed */
-static int uci_parse_history(struct uci_context *ctx, FILE *stream, struct uci_package *p)
-{
-	struct uci_parse_context *pctx;
-	int changes = 0;
-
-	/* make sure no memory from previous parse attempts is leaked */
-	uci_cleanup(ctx);
-
-	pctx = (struct uci_parse_context *) uci_malloc(ctx, sizeof(struct uci_parse_context));
-	ctx->pctx = pctx;
-	pctx->file = stream;
-
-	while (!feof(pctx->file)) {
-		uci_getln(ctx, 0);
-		if (!pctx->buf[0])
-			continue;
-
-		/*
-		 * ignore parse errors in single lines, we want to preserve as much
-		 * history as possible
-		 */
-		UCI_TRAP_SAVE(ctx, error);
-		uci_parse_history_line(ctx, p, pctx->buf);
-		UCI_TRAP_RESTORE(ctx);
-		changes++;
-error:
-		continue;
-	}
-
-	/* no error happened, we can get rid of the parser context now */
-	uci_cleanup(ctx);
-	return changes;
-}
-
-/* returns the number of changes that were successfully parsed */
-static int uci_load_history_file(struct uci_context *ctx, struct uci_package *p, char *filename, FILE **f, bool flush)
-{
-	FILE *stream = NULL;
-	int changes = 0;
-
-	UCI_TRAP_SAVE(ctx, done);
-	stream = uci_open_stream(ctx, filename, SEEK_SET, flush, false);
-	if (p)
-		changes = uci_parse_history(ctx, stream, p);
-	UCI_TRAP_RESTORE(ctx);
-done:
-	if (f)
-		*f = stream;
-	else if (stream)
-		uci_close_stream(stream);
-	return changes;
-}
-
-/* returns the number of changes that were successfully parsed */
-__private int uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush)
-{
-	struct uci_element *e;
-	char *filename = NULL;
-	FILE *f = NULL;
-	int changes = 0;
-
-	if (!p->has_history)
-		return 0;
-
-	uci_foreach_element(&ctx->history_path, e) {
-		if ((asprintf(&filename, "%s/%s", e->name, p->e.name) < 0) || !filename)
-			UCI_THROW(ctx, UCI_ERR_MEM);
-
-		uci_load_history_file(ctx, p, filename, NULL, false);
-		free(filename);
-	}
-
-	if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
-		UCI_THROW(ctx, UCI_ERR_MEM);
-
-	changes = uci_load_history_file(ctx, p, filename, &f, flush);
-	if (flush && f && (changes > 0)) {
-		rewind(f);
-		if (ftruncate(fileno(f), 0) < 0) {
-			uci_close_stream(f);
-			UCI_THROW(ctx, UCI_ERR_IO);
-		}
-	}
-	if (filename)
-		free(filename);
-	uci_close_stream(f);
-	ctx->err = 0;
-	return changes;
-}
-
-static void uci_filter_history(struct uci_context *ctx, const char *name, const char *section, const char *option)
-{
-	struct uci_parse_context *pctx;
-	struct uci_element *e, *tmp;
-	struct uci_list list;
-	char *filename = NULL;
-	struct uci_ptr ptr;
-	FILE *f = NULL;
-
-	uci_list_init(&list);
-	uci_alloc_parse_context(ctx);
-	pctx = ctx->pctx;
-
-	if ((asprintf(&filename, "%s/%s", ctx->savedir, name) < 0) || !filename)
-		UCI_THROW(ctx, UCI_ERR_MEM);
-
-	UCI_TRAP_SAVE(ctx, done);
-	f = uci_open_stream(ctx, filename, SEEK_SET, true, false);
-	pctx->file = f;
-	while (!feof(f)) {
-		struct uci_element *e;
-		char *buf;
-
-		uci_getln(ctx, 0);
-		buf = pctx->buf;
-		if (!buf[0])
-			continue;
-
-		/* NB: need to allocate the element before the call to 
-		 * uci_parse_history_tuple, otherwise the original string 
-		 * gets modified before it is saved */
-		e = uci_alloc_generic(ctx, UCI_TYPE_HISTORY, pctx->buf, sizeof(struct uci_element));
-		uci_list_add(&list, &e->list);
-
-		uci_parse_history_tuple(ctx, &buf, &ptr);
-		if (section) {
-			if (!ptr.section || (strcmp(section, ptr.section) != 0))
-				continue;
-		}
-		if (option) {
-			if (!ptr.option || (strcmp(option, ptr.option) != 0))
-				continue;
-		}
-		/* match, drop this element again */
-		uci_free_element(e);
-	}
-
-	/* rebuild the history file */
-	rewind(f);
-	if (ftruncate(fileno(f), 0) < 0)
-		UCI_THROW(ctx, UCI_ERR_IO);
-	uci_foreach_element_safe(&list, tmp, e) {
-		fprintf(f, "%s\n", e->name);
-		uci_free_element(e);
-	}
-	UCI_TRAP_RESTORE(ctx);
-
-done:
-	if (filename)
-		free(filename);
-	uci_close_stream(pctx->file);
-	uci_foreach_element_safe(&list, tmp, e) {
-		uci_free_element(e);
-	}
-	uci_cleanup(ctx);
-}
-
-int uci_revert(struct uci_context *ctx, struct uci_ptr *ptr)
-{
-	char *package = NULL;
-	char *section = NULL;
-	char *option = NULL;
-
-	UCI_HANDLE_ERR(ctx);
-	expand_ptr(ctx, ptr, false);
-	UCI_ASSERT(ctx, ptr->p->has_history);
-
-	/* 
-	 * - flush unwritten changes
-	 * - save the package name
-	 * - unload the package
-	 * - filter the history
-	 * - reload the package
-	 */
-	UCI_TRAP_SAVE(ctx, error);
-	UCI_INTERNAL(uci_save, ctx, ptr->p);
-
-	/* NB: need to clone package, section and option names, 
-	 * as they may get freed on uci_free_package() */
-	package = uci_strdup(ctx, ptr->p->e.name);
-	if (ptr->section)
-		section = uci_strdup(ctx, ptr->section);
-	if (ptr->option)
-		option = uci_strdup(ctx, ptr->option);
-
-	uci_free_package(&ptr->p);
-	uci_filter_history(ctx, package, section, option);
-
-	UCI_INTERNAL(uci_load, ctx, package, &ptr->p);
-	UCI_TRAP_RESTORE(ctx);
-	ctx->err = 0;
-
-error:
-	if (package)
-		free(package);
-	if (section)
-		free(section);
-	if (option)
-		free(option);
-	if (ctx->err)
-		UCI_THROW(ctx, ctx->err);
-	return 0;
-}
-
-int uci_save(struct uci_context *ctx, struct uci_package *p)
-{
-	FILE *f = NULL;
-	char *filename = NULL;
-	struct uci_element *e, *tmp;
-	struct stat statbuf;
-
-	UCI_HANDLE_ERR(ctx);
-	UCI_ASSERT(ctx, p != NULL);
-
-	/* 
-	 * if the config file was outside of the /etc/config path,
-	 * don't save the history to a file, update the real file
-	 * directly.
-	 * does not modify the uci_package pointer
-	 */
-	if (!p->has_history)
-		return uci_commit(ctx, &p, false);
-
-	if (uci_list_empty(&p->history))
-		return 0;
-
-	if (stat(ctx->savedir, &statbuf) < 0)
-		mkdir(ctx->savedir, UCI_DIRMODE);
-	else if ((statbuf.st_mode & S_IFMT) != S_IFDIR)
-		UCI_THROW(ctx, UCI_ERR_IO);
-
-	if ((asprintf(&filename, "%s/%s", ctx->savedir, p->e.name) < 0) || !filename)
-		UCI_THROW(ctx, UCI_ERR_MEM);
-
-	uci_foreach_element(&ctx->hooks, tmp) {
-		struct uci_hook *hook = uci_to_hook(tmp);
-
-		if (!hook->ops->set)
-			continue;
-
-		uci_foreach_element(&p->history, e) {
-			hook->ops->set(hook->ops, p, uci_to_history(e));
-		}
-	}
-
-	ctx->err = 0;
-	UCI_TRAP_SAVE(ctx, done);
-	f = uci_open_stream(ctx, filename, SEEK_END, true, true);
-	UCI_TRAP_RESTORE(ctx);
-
-	uci_foreach_element_safe(&p->history, tmp, e) {
-		struct uci_history *h = uci_to_history(e);
-		char *prefix = "";
-
-		switch(h->cmd) {
-		case UCI_CMD_REMOVE:
-			prefix = "-";
-			break;
-		case UCI_CMD_RENAME:
-			prefix = "@";
-			break;
-		case UCI_CMD_ADD:
-			prefix = "+";
-			break;
-		case UCI_CMD_REORDER:
-			prefix = "^";
-			break;
-		case UCI_CMD_LIST_ADD:
-			prefix = "|";
-			break;
-		default:
-			break;
-		}
-
-		fprintf(f, "%s%s.%s", prefix, p->e.name, h->section);
-		if (e->name)
-			fprintf(f, ".%s", e->name);
-
-		if (h->cmd == UCI_CMD_REMOVE)
-			fprintf(f, "\n");
-		else
-			fprintf(f, "=%s\n", h->value);
-		uci_free_history(h);
-	}
-
-done:
-	uci_close_stream(f);
-	if (filename)
-		free(filename);
-	if (ctx->err)
-		UCI_THROW(ctx, ctx->err);
-
-	return 0;
-}
-
-
diff --git a/libuci.c b/libuci.c
index 5b22ef1..1a09fc7 100644
--- a/libuci.c
+++ b/libuci.c
@@ -44,7 +44,7 @@ static void uci_unload_plugin(struct uci_context *ctx, struct uci_plugin *p);
 
 #include "uci_internal.h"
 #include "list.c"
-#include "history.c"
+#include "delta.c"
 
 /* exported functions */
 struct uci_context *uci_alloc_context(void)
@@ -57,11 +57,11 @@ struct uci_context *uci_alloc_context(void)
 
 	memset(ctx, 0, sizeof(struct uci_context));
 	uci_list_init(&ctx->root);
-	uci_list_init(&ctx->history_path);
+	uci_list_init(&ctx->delta_path);
 	uci_list_init(&ctx->backends);
 	uci_list_init(&ctx->hooks);
 	uci_list_init(&ctx->plugins);
-	ctx->flags = UCI_FLAG_STRICT | UCI_FLAG_SAVED_HISTORY;
+	ctx->flags = UCI_FLAG_STRICT | UCI_FLAG_SAVED_DELTA;
 
 	ctx->confdir = (char *) uci_confdir;
 	ctx->savedir = (char *) uci_savedir;
@@ -87,7 +87,7 @@ void uci_free_context(struct uci_context *ctx)
 		struct uci_package *p = uci_to_package(e);
 		uci_free_package(&p);
 	}
-	uci_foreach_element_safe(&ctx->history_path, tmp, e) {
+	uci_foreach_element_safe(&ctx->delta_path, tmp, e) {
 		uci_free_element(e);
 	}
 	UCI_TRAP_RESTORE(ctx);
diff --git a/list.c b/list.c
index 1a080fa..cee1063 100644
--- a/list.c
+++ b/list.c
@@ -224,8 +224,8 @@ uci_alloc_package(struct uci_context *ctx, const char *name)
 	p = uci_alloc_element(ctx, package, name, 0);
 	p->ctx = ctx;
 	uci_list_init(&p->sections);
-	uci_list_init(&p->history);
-	uci_list_init(&p->saved_history);
+	uci_list_init(&p->delta);
+	uci_list_init(&p->saved_delta);
 	return p;
 }
 
@@ -243,11 +243,11 @@ uci_free_package(struct uci_package **package)
 	uci_foreach_element_safe(&p->sections, tmp, e) {
 		uci_free_section(uci_to_section(e));
 	}
-	uci_foreach_element_safe(&p->history, tmp, e) {
-		uci_free_history(uci_to_history(e));
+	uci_foreach_element_safe(&p->delta, tmp, e) {
+		uci_free_delta(uci_to_delta(e));
 	}
-	uci_foreach_element_safe(&p->saved_history, tmp, e) {
-		uci_free_history(uci_to_history(e));
+	uci_foreach_element_safe(&p->saved_delta, tmp, e) {
+		uci_free_delta(uci_to_delta(e));
 	}
 	uci_free_element(&p->e);
 	*package = NULL;
@@ -452,8 +452,8 @@ static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, b
 	struct uci_package *p;
 
 	p = ptr->p;
-	if (!internal && p->has_history)
-		uci_add_history(ctx, &p->history, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_LIST_ADD, ptr->section, ptr->option, ptr->value);
 
 	e = uci_alloc_generic(ctx, UCI_TYPE_ITEM, ptr->value, sizeof(struct uci_option));
 	uci_list_add(&ptr->o->v.list, &e->list);
@@ -461,7 +461,7 @@ static void uci_add_element_list(struct uci_context *ctx, struct uci_ptr *ptr, b
 
 int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
 {
-	/* NB: UCI_INTERNAL use means without history tracking */
+	/* NB: UCI_INTERNAL use means without delta tracking */
 	bool internal = ctx->internal;
 	struct uci_element *e;
 	struct uci_package *p;
@@ -475,8 +475,8 @@ int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr)
 	UCI_ASSERT(ctx, ptr->s);
 	UCI_ASSERT(ctx, ptr->value);
 
-	if (!internal && p->has_history)
-		uci_add_history(ctx, &p->history, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_RENAME, ptr->section, ptr->option, ptr->value);
 
 	n = uci_strdup(ctx, ptr->value);
 	if (e->name)
@@ -497,9 +497,9 @@ int uci_reorder_section(struct uci_context *ctx, struct uci_section *s, int pos)
 	UCI_HANDLE_ERR(ctx);
 
 	uci_list_set_pos(&s->package->sections, &s->e.list, pos);
-	if (!ctx->internal && p->has_history) {
+	if (!ctx->internal && p->has_delta) {
 		sprintf(order, "%d", pos);
-		uci_add_history(ctx, &p->history, UCI_CMD_REORDER, s->e.name, NULL, order);
+		uci_add_delta(ctx, &p->delta, UCI_CMD_REORDER, s->e.name, NULL, order);
 	}
 
 	return 0;
@@ -515,8 +515,8 @@ int uci_add_section(struct uci_context *ctx, struct uci_package *p, const char *
 	s = uci_alloc_section(p, type, NULL);
 	uci_fixup_section(ctx, s);
 	*res = s;
-	if (!internal && p->has_history)
-		uci_add_history(ctx, &p->history, UCI_CMD_ADD, s->e.name, NULL, type);
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_ADD, s->e.name, NULL, type);
 
 	return 0;
 }
@@ -535,8 +535,8 @@ int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 
 	UCI_ASSERT(ctx, ptr->s);
 
-	if (!internal && p->has_history)
-		uci_add_history(ctx, &p->history, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
+	if (!internal && p->has_delta)
+		uci_add_delta(ctx, &p->delta, UCI_CMD_REMOVE, ptr->section, ptr->option, NULL);
 
 	uci_free_any(&e);
 
@@ -550,7 +550,7 @@ int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr)
 
 int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 {
-	/* NB: UCI_INTERNAL use means without history tracking */
+	/* NB: UCI_INTERNAL use means without delta tracking */
 	bool internal = ctx->internal;
 	struct uci_option *prev = NULL;
 	const char *value2 = NULL;
@@ -591,7 +591,7 @@ int uci_add_list(struct uci_context *ctx, struct uci_ptr *ptr)
 
 int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
 {
-	/* NB: UCI_INTERNAL use means without history tracking */
+	/* NB: UCI_INTERNAL use means without delta tracking */
 	bool internal = ctx->internal;
 
 	UCI_HANDLE_ERR(ctx);
@@ -644,8 +644,8 @@ int uci_set(struct uci_context *ctx, struct uci_ptr *ptr)
 		UCI_THROW(ctx, UCI_ERR_INVAL);
 	}
 
-	if (!internal && ptr->p->has_history)
-		uci_add_history(ctx, &ptr->p->history, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
+	if (!internal && ptr->p->has_delta)
+		uci_add_delta(ctx, &ptr->p->delta, UCI_CMD_CHANGE, ptr->section, ptr->option, ptr->value);
 
 	return 0;
 }
diff --git a/lua/uci.c b/lua/uci.c
index b355420..efa8c1a 100644
--- a/lua/uci.c
+++ b/lua/uci.c
@@ -689,10 +689,10 @@ uci_lua_revert(lua_State *L)
 static void
 uci_lua_add_change(lua_State *L, struct uci_element *e)
 {
-	struct uci_history *h;
+	struct uci_delta *h;
 	const char *name;
 
-	h = uci_to_history(e);
+	h = uci_to_delta(e);
 	if (!h->section)
 		return;
 
@@ -728,14 +728,14 @@ uci_lua_changes_pkg(lua_State *L, struct uci_context *ctx, const char *package)
 			return;
 	}
 
-	if (uci_list_empty(&p->history) && uci_list_empty(&p->saved_history))
+	if (uci_list_empty(&p->delta) && uci_list_empty(&p->saved_delta))
 		goto done;
 
 	lua_newtable(L);
-	uci_foreach_element(&p->saved_history, e) {
+	uci_foreach_element(&p->saved_delta, e) {
 		uci_lua_add_change(L, e);
 	}
-	uci_foreach_element(&p->history, e) {
+	uci_foreach_element(&p->delta, e) {
 		uci_lua_add_change(L, e);
 	}
 	lua_setfield(L, -2, p->e.name);
@@ -810,14 +810,14 @@ uci_lua_get_savedir(lua_State *L)
 }
 
 static int
-uci_lua_add_history(lua_State *L)
+uci_lua_add_delta(lua_State *L)
 {
 	struct uci_context *ctx;
 	int ret, offset = 0;
 
 	ctx = find_context(L, &offset);
 	luaL_checkstring(L, 1 + offset);
-	ret = uci_add_history_path(ctx, lua_tostring(L, -1));
+	ret = uci_add_delta_path(ctx, lua_tostring(L, -1));
 	return uci_push_status(L, ctx, false);
 }
 
@@ -902,7 +902,7 @@ static const luaL_Reg uci[] = {
 	{ "reorder", uci_lua_reorder },
 	{ "changes", uci_lua_changes },
 	{ "foreach", uci_lua_foreach },
-	{ "add_history", uci_lua_add_history },
+	{ "add_delta", uci_lua_add_delta },
 	{ "load_plugins", uci_lua_load_plugins },
 	{ "get_confdir", uci_lua_get_confdir },
 	{ "set_confdir", uci_lua_set_confdir },
diff --git a/uci.h b/uci.h
index 4fa0b6a..5644ca8 100644
--- a/uci.h
+++ b/uci.h
@@ -62,7 +62,7 @@ struct uci_element;
 struct uci_package;
 struct uci_section;
 struct uci_option;
-struct uci_history;
+struct uci_delta;
 struct uci_context;
 struct uci_backend;
 struct uci_parse_context;
@@ -104,7 +104,7 @@ extern void uci_get_errorstr(struct uci_context *ctx, char **dest, const char *s
  * @single: ignore the 'package' keyword and parse everything into a single package
  *
  * the name parameter is for config files that don't explicitly use the 'package <...>' keyword
- * if 'package' points to a non-null struct pointer, enable history tracking and merge 
+ * if 'package' points to a non-null struct pointer, enable delta tracking and merge 
  */
 extern int uci_import(struct uci_context *ctx, FILE *stream, const char *name, struct uci_package **package, bool single);
 
@@ -204,7 +204,7 @@ extern int uci_rename(struct uci_context *ctx, struct uci_ptr *ptr);
 extern int uci_delete(struct uci_context *ctx, struct uci_ptr *ptr);
 
 /**
- * uci_save: save change history for a package
+ * uci_save: save change delta for a package
  * @ctx: uci context
  * @p: uci_package struct
  */
@@ -214,7 +214,7 @@ extern int uci_save(struct uci_context *ctx, struct uci_package *p);
  * uci_commit: commit changes to a package
  * @ctx: uci context
  * @p: uci_package struct pointer
- * @overwrite: overwrite existing config data and flush history
+ * @overwrite: overwrite existing config data and flush delta
  *
  * committing may reload the whole uci_package data,
  * the supplied pointer is updated accordingly
@@ -230,7 +230,7 @@ extern int uci_commit(struct uci_context *ctx, struct uci_package **p, bool over
 extern int uci_list_configs(struct uci_context *ctx, char ***list);
 
 /** 
- * uci_set_savedir: override the default history save directory
+ * uci_set_savedir: override the default delta save directory
  * @ctx: uci context
  * @dir: directory name
  */
@@ -244,14 +244,14 @@ extern int uci_set_savedir(struct uci_context *ctx, const char *dir);
 extern int uci_set_confdir(struct uci_context *ctx, const char *dir);
 
 /**
- * uci_add_history_path: add a directory to the search path for change history files
+ * uci_add_delta_path: add a directory to the search path for change delta files
  * @ctx: uci context
  * @dir: directory name
  *
  * This function allows you to add directories, which contain 'overlays'
  * for the active config, that will never be committed.
  */
-extern int uci_add_history_path(struct uci_context *ctx, const char *dir);
+extern int uci_add_delta_path(struct uci_context *ctx, const char *dir);
 
 /**
  * uci_revert: revert all changes to a config item
@@ -336,7 +336,7 @@ int uci_parse_ptr(struct uci_context *ctx, struct uci_ptr *ptr, char *str);
 /* UCI data structures */
 enum uci_type {
 	UCI_TYPE_UNSPEC = 0,
-	UCI_TYPE_HISTORY = 1,
+	UCI_TYPE_DELTA = 1,
 	UCI_TYPE_PACKAGE = 2,
 	UCI_TYPE_SECTION = 3,
 	UCI_TYPE_OPTION = 4,
@@ -356,7 +356,7 @@ enum uci_flags {
 	UCI_FLAG_STRICT =        (1 << 0), /* strict mode for the parser */
 	UCI_FLAG_PERROR =        (1 << 1), /* print parser error messages */
 	UCI_FLAG_EXPORT_NAME =   (1 << 2), /* when exporting, name unnamed sections */
-	UCI_FLAG_SAVED_HISTORY = (1 << 3), /* store the saved history in memory as well */
+	UCI_FLAG_SAVED_DELTA = (1 << 3), /* store the saved delta in memory as well */
 };
 
 struct uci_element
@@ -396,8 +396,8 @@ struct uci_context
 	char *confdir;
 	char *savedir;
 
-	/* search path for history files */
-	struct uci_list history_path;
+	/* search path for delta files */
+	struct uci_list delta_path;
 
 	/* private: */
 	int err;
@@ -416,15 +416,15 @@ struct uci_package
 	struct uci_element e;
 	struct uci_list sections;
 	struct uci_context *ctx;
-	bool has_history;
+	bool has_delta;
 	char *path;
 
 	/* private: */
 	struct uci_backend *backend;
 	void *priv;
 	int n_section;
-	struct uci_list history;
-	struct uci_list saved_history;
+	struct uci_list delta;
+	struct uci_list saved_delta;
 };
 
 struct uci_section
@@ -456,7 +456,7 @@ enum uci_command {
 	UCI_CMD_LIST_ADD,
 };
 
-struct uci_history
+struct uci_delta
 {
 	struct uci_element e;
 	enum uci_command cmd;
@@ -487,7 +487,7 @@ struct uci_ptr
 struct uci_hook_ops
 {
 	void (*load)(const struct uci_hook_ops *ops, struct uci_package *p);
-	void (*set)(const struct uci_hook_ops *ops, struct uci_package *p, struct uci_history *e);
+	void (*set)(const struct uci_hook_ops *ops, struct uci_package *p, struct uci_delta *e);
 };
 
 struct uci_hook
@@ -575,7 +575,7 @@ struct uci_plugin
 
 /* wrappers for dynamic type handling */
 #define uci_type_backend UCI_TYPE_BACKEND
-#define uci_type_history UCI_TYPE_HISTORY
+#define uci_type_delta UCI_TYPE_DELTA
 #define uci_type_package UCI_TYPE_PACKAGE
 #define uci_type_section UCI_TYPE_SECTION
 #define uci_type_option UCI_TYPE_OPTION
@@ -586,7 +586,7 @@ struct uci_plugin
 #ifdef UCI_DEBUG_TYPECAST
 static const char *uci_typestr[] = {
 	[uci_type_backend] = "backend",
-	[uci_type_history] = "history",
+	[uci_type_delta] = "delta",
 	[uci_type_package] = "package",
 	[uci_type_section] = "section",
 	[uci_type_option] = "option",
@@ -609,7 +609,7 @@ static void uci_typecast_error(int from, int to)
 	}
 
 BUILD_CAST(backend)
-BUILD_CAST(history)
+BUILD_CAST(delta)
 BUILD_CAST(package)
 BUILD_CAST(section)
 BUILD_CAST(option)
@@ -618,7 +618,7 @@ BUILD_CAST(plugin)
 
 #else
 #define uci_to_backend(ptr) container_of(ptr, struct uci_backend, e)
-#define uci_to_history(ptr) container_of(ptr, struct uci_history, e)
+#define uci_to_delta(ptr) container_of(ptr, struct uci_delta, e)
 #define uci_to_package(ptr) container_of(ptr, struct uci_package, e)
 #define uci_to_section(ptr) container_of(ptr, struct uci_section, e)
 #define uci_to_option(ptr)  container_of(ptr, struct uci_option, e)
diff --git a/uci_internal.h b/uci_internal.h
index 7ce00d0..728920d 100644
--- a/uci_internal.h
+++ b/uci_internal.h
@@ -44,8 +44,8 @@ __plugin void *uci_malloc(struct uci_context *ctx, size_t size);
 __plugin void *uci_realloc(struct uci_context *ctx, void *ptr, size_t size);
 __plugin char *uci_strdup(struct uci_context *ctx, const char *str);
 __plugin bool uci_validate_str(const char *str, bool name);
-__plugin void uci_add_history(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value);
-__plugin void uci_free_history(struct uci_history *h);
+__plugin void uci_add_delta(struct uci_context *ctx, struct uci_list *list, int cmd, const char *section, const char *option, const char *value);
+__plugin void uci_free_delta(struct uci_delta *h);
 __plugin struct uci_package *uci_alloc_package(struct uci_context *ctx, const char *name);
 
 __private FILE *uci_open_stream(struct uci_context *ctx, const char *filename, int pos, bool write, bool create);
@@ -60,7 +60,7 @@ __private struct uci_element *uci_lookup_list(struct uci_list *list, const char
 __private void uci_fixup_section(struct uci_context *ctx, struct uci_section *s);
 __private void uci_free_package(struct uci_package **package);
 
-__private int uci_load_history(struct uci_context *ctx, struct uci_package *p, bool flush);
+__private int uci_load_delta(struct uci_context *ctx, struct uci_package *p, bool flush);
 
 static inline bool uci_validate_package(const char *str)
 {