[PATCH v2 6/9] filter: add lua support
Jason A. Donenfeld
Jason at zx2c4.com
Mon Jan 13 15:00:27 CET 2014
Signed-off-by: Jason A. Donenfeld <Jason at zx2c4.com>
---
cgit.mk | 22 ++++++-
cgitrc.5.txt | 29 ++++++++++
filter.c | 186 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 234 insertions(+), 3 deletions(-)
diff --git a/cgit.mk b/cgit.mk
index 9d6dea8..25f2eab 100644
--- a/cgit.mk
+++ b/cgit.mk
@@ -25,6 +25,25 @@ ifdef NO_C99_FORMAT
CFLAGS += -DNO_C99_FORMAT
endif
+ifdef NO_LUA
+ CFLAGS += -DNO_LUA
+else
+
+ifeq (VANILLA,$(LUA_IMPLEMENTATION))
+ CFLAGS += -llua
+else
+ LUAJIT_LIBS := $(shell pkg-config --libs luajit)
+ LUAJIT_CFLAGS := $(shell pkg-config --cflags luajit)
+ CGIT_LIBS += $(LUAJIT_LIBS)
+ CFLAGS += $(LUAJIT_CFLAGS)
+endif
+
+endif
+
+CGIT_LIBS += -ldl
+
+
+
CGIT_OBJ_NAMES += cgit.o
CGIT_OBJ_NAMES += cache.o
CGIT_OBJ_NAMES += cmd.o
@@ -61,9 +80,6 @@ $(CGIT_VERSION_OBJS): $(CGIT_PREFIX)VERSION
$(CGIT_VERSION_OBJS): EXTRA_CPPFLAGS = \
-DCGIT_VERSION='"$(CGIT_VERSION)"'
-CGIT_LIBS += -ldl
-
-
# Git handles dependencies using ":=" so dependencies in CGIT_OBJ are not
# handled by that and we must handle them ourselves.
cgit_dep_files := $(foreach f,$(CGIT_OBJS),$(dir $f).depend/$(notdir $f).d)
diff --git a/cgitrc.5.txt b/cgitrc.5.txt
index 60159f6..78f33c8 100644
--- a/cgitrc.5.txt
+++ b/cgitrc.5.txt
@@ -564,6 +564,35 @@ specification with the relevant string; available values are:
'exec:'::
The default "one process per filter" mode.
+'lua:'::
+ Executes the script using a built-in Lua interpreter. The script is
+ loaded once per execution of cgit, and may be called multiple times
+ during cgit's lifetime, making it a good choice for repeated filters
+ such as the 'email filter'. It responds to three functions:
+
+ 'filter_open(argument1, argument2, argument3, ...)'::
+ This is called upon activation of the filter for a particular
+ set of data.
+ 'filter_write(buffer)'::
+ This is called whenever cgit writes data to the webpage.
+ 'filter_close()'::
+ This is called when the current filtering operation is
+ completed.
+
+ Additionally, cgit exposes to the Lua the following built-in functions:
+
+ 'html(str)'::
+ Writes 'str' to the webpage.
+ 'html_txt(str)'::
+ HTML escapes and writes 'str' to the webpage.
+ 'html_attr(str)'::
+ HTML escapes for an attribute and writes "str' to the webpage.
+ 'html_url_path(str)'::
+ URL escapes for a path and writes 'str' to the webpage.
+ 'html_url_arg(str)'::
+ URL escapes for an argument and writes 'str' to the webpage.
+
+
Parameters are provided to filters as follows.
about filter::
diff --git a/filter.c b/filter.c
index f5a5992..3702585 100644
--- a/filter.c
+++ b/filter.c
@@ -7,12 +7,19 @@
*/
#include "cgit.h"
+#include "html.h"
#include <sys/types.h>
#include <sys/wait.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>
#include <dlfcn.h>
+#include <errno.h>
+#ifndef NO_LUA
+#include <lua.h>
+#include <lualib.h>
+#include <lauxlib.h>
+#endif
static ssize_t (*libc_write)(int fd, const void *buf, size_t count);
static ssize_t (*filter_write)(struct cgit_filter *base, const void *buf, size_t count) = NULL;
@@ -164,6 +171,182 @@ void cgit_exec_filter_init(struct cgit_exec_filter *filter, char *cmd, char **ar
filter->base.argument_count = 0;
}
+#ifndef NO_LUA
+struct lua_filter {
+ struct cgit_filter base;
+ char *script_file;
+ lua_State *lua_state;
+};
+
+static void error_lua_filter(struct lua_filter *filter)
+{
+ die("Lua error in %s: %s", filter->script_file, lua_tostring(filter->lua_state, -1));
+ lua_pop(filter->lua_state, 1);
+}
+
+static ssize_t write_lua_filter(struct cgit_filter *base, const void *buf, size_t count)
+{
+ struct lua_filter *filter = (struct lua_filter *) base;
+
+ lua_getglobal(filter->lua_state, "filter_write");
+ lua_pushlstring(filter->lua_state, buf, count);
+ if (lua_pcall(filter->lua_state, 1, 0, 0)) {
+ error_lua_filter(filter);
+ errno = EIO;
+ return -1;
+ }
+ return count;
+}
+
+static inline int hook_lua_filter(lua_State *lua_state, void (*fn)(const char *txt))
+{
+ const char *str;
+ ssize_t (*save_filter_write)(struct cgit_filter *base, const void *buf, size_t count);
+ struct cgit_filter *save_filter;
+
+ str = lua_tostring(lua_state, 1);
+ if (!str)
+ return 0;
+
+ save_filter_write = filter_write;
+ save_filter = current_write_filter;
+ unhook_write();
+ fn(str);
+ hook_write(save_filter, save_filter_write);
+
+ return 0;
+}
+
+static int html_lua_filter(lua_State *lua_state)
+{
+ return hook_lua_filter(lua_state, html);
+}
+
+static int html_txt_lua_filter(lua_State *lua_state)
+{
+ return hook_lua_filter(lua_state, html_txt);
+}
+
+static int html_attr_lua_filter(lua_State *lua_state)
+{
+ return hook_lua_filter(lua_state, html_attr);
+}
+
+static int html_url_path_lua_filter(lua_State *lua_state)
+{
+ return hook_lua_filter(lua_state, html_url_path);
+}
+
+static int html_url_arg_lua_filter(lua_State *lua_state)
+{
+ return hook_lua_filter(lua_state, html_url_arg);
+}
+
+static void cleanup_lua_filter(struct cgit_filter *base)
+{
+ struct lua_filter *filter = (struct lua_filter *) base;
+
+ if (!filter->lua_state)
+ return;
+
+ lua_close(filter->lua_state);
+ filter->lua_state = NULL;
+ if (filter->script_file) {
+ free(filter->script_file);
+ filter->script_file = NULL;
+ }
+}
+
+static int init_lua_filter(struct lua_filter *filter)
+{
+ if (filter->lua_state)
+ return 0;
+
+ if (!(filter->lua_state = luaL_newstate()))
+ return 1;
+
+ luaL_openlibs(filter->lua_state);
+
+ lua_pushcfunction(filter->lua_state, html_lua_filter);
+ lua_setglobal(filter->lua_state, "html");
+ lua_pushcfunction(filter->lua_state, html_txt_lua_filter);
+ lua_setglobal(filter->lua_state, "html_txt");
+ lua_pushcfunction(filter->lua_state, html_attr_lua_filter);
+ lua_setglobal(filter->lua_state, "html_attr");
+ lua_pushcfunction(filter->lua_state, html_url_path_lua_filter);
+ lua_setglobal(filter->lua_state, "html_url_path");
+ lua_pushcfunction(filter->lua_state, html_url_arg_lua_filter);
+ lua_setglobal(filter->lua_state, "html_url_arg");
+
+ if (luaL_dofile(filter->lua_state, filter->script_file)) {
+ error_lua_filter(filter);
+ lua_close(filter->lua_state);
+ filter->lua_state = NULL;
+ return 1;
+ }
+ return 0;
+}
+
+static int open_lua_filter(struct cgit_filter *base, va_list ap)
+{
+ struct lua_filter *filter = (struct lua_filter *) base;
+ int i;
+
+ if (init_lua_filter(filter))
+ return 1;
+
+ hook_write(base, write_lua_filter);
+
+ lua_getglobal(filter->lua_state, "filter_open");
+ for (i = 0; i < filter->base.argument_count; ++i)
+ lua_pushstring(filter->lua_state, va_arg(ap, char *));
+ if (lua_pcall(filter->lua_state, filter->base.argument_count, 0, 0)) {
+ error_lua_filter(filter);
+ return 1;
+ }
+ return 0;
+}
+
+static int close_lua_filter(struct cgit_filter *base)
+{
+ struct lua_filter *filter = (struct lua_filter *) base;
+ int ret = 0;
+
+ lua_getglobal(filter->lua_state, "filter_close");
+ if (lua_pcall(filter->lua_state, 0, 0, 0)) {
+ error_lua_filter(filter);
+ ret = 1;
+ }
+ unhook_write();
+ return ret;
+}
+
+static void fprintf_lua_filter(struct cgit_filter *base, FILE *f, const char *prefix)
+{
+ struct lua_filter *filter = (struct lua_filter *) base;
+ fprintf(f, "%slua:%s\n", prefix, filter->script_file);
+}
+
+
+static struct cgit_filter *new_lua_filter(const char *cmd, int argument_count)
+{
+ struct lua_filter *filter;
+
+ filter = xmalloc(sizeof(*filter));
+ memset(filter, 0, sizeof(*filter));
+ filter->base.open = open_lua_filter;
+ filter->base.close = close_lua_filter;
+ filter->base.fprintf = fprintf_lua_filter;
+ filter->base.cleanup = cleanup_lua_filter;
+ filter->base.argument_count = argument_count;
+ filter->script_file = xstrdup(cmd);
+
+ return &filter->base;
+}
+
+#endif
+
+
int cgit_open_filter(struct cgit_filter *filter, ...)
{
int result;
@@ -191,6 +374,9 @@ static const struct {
struct cgit_filter *(*ctor)(const char *cmd, int argument_count);
} filter_specs[] = {
{ "exec", new_exec_filter },
+#ifndef NO_LUA
+ { "lua", new_lua_filter },
+#endif
};
struct cgit_filter *cgit_new_filter(const char *cmd, filter_type filtertype)
--
1.8.5.2
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