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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 15:26:00 +0000
commit830407e88f9d40d954356c3754f2647f91d5c06a (patch)
treed6a0ece6feea91f3c656166dbaa884ef8a29740e /modules/policy/lua-aho-corasick/ac_lua.cxx
parentInitial commit. (diff)
downloadknot-resolver-830407e88f9d40d954356c3754f2647f91d5c06a.tar.xz
knot-resolver-830407e88f9d40d954356c3754f2647f91d5c06a.zip
Adding upstream version 5.6.0.upstream/5.6.0upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'modules/policy/lua-aho-corasick/ac_lua.cxx')
-rw-r--r--modules/policy/lua-aho-corasick/ac_lua.cxx173
1 files changed, 173 insertions, 0 deletions
diff --git a/modules/policy/lua-aho-corasick/ac_lua.cxx b/modules/policy/lua-aho-corasick/ac_lua.cxx
new file mode 100644
index 0000000..ad7307e
--- /dev/null
+++ b/modules/policy/lua-aho-corasick/ac_lua.cxx
@@ -0,0 +1,173 @@
+// Interface functions for libac.so
+//
+#include <vector>
+#include <string>
+#include "ac_slow.hpp"
+#include "ac_fast.hpp"
+#include "ac.h" // for the definition of ac_result_t
+#include "ac_util.hpp"
+
+extern "C" {
+ #include <lua.h>
+ #include <lauxlib.h>
+}
+
+#if defined(USE_SLOW_VER)
+#error "Not going to implement it"
+#endif
+
+using namespace std;
+static const char* tname = "aho-corasick";
+
+class BufAlloc : public Buf_Allocator {
+public:
+ BufAlloc(lua_State* L) : _L(L) {}
+ virtual AC_Buffer* alloc(int sz) {
+ return (AC_Buffer*)lua_newuserdata (_L, sz);
+ }
+
+ // Let GC to take care.
+ virtual void free() {}
+
+private:
+ lua_State* _L;
+};
+
+static bool
+_create_helper(lua_State* L, const vector<const char*>& str_v,
+ const vector<unsigned int>& strlen_v) {
+ ASSERT(str_v.size() == strlen_v.size());
+
+ ACS_Constructor acc;
+ BufAlloc ba(L);
+
+ // Step 1: construt the slow version.
+ unsigned int strnum = str_v.size();
+ const char** str_vect = new const char*[strnum];
+ unsigned int* strlen_vect = new unsigned int[strnum];
+
+ int idx = 0;
+ for (vector<const char*>::const_iterator i = str_v.begin(), e = str_v.end();
+ i != e; i++) {
+ str_vect[idx++] = *i;
+ }
+
+ idx = 0;
+ for (vector<unsigned int>::const_iterator i = strlen_v.begin(),
+ e = strlen_v.end(); i != e; i++) {
+ strlen_vect[idx++] = *i;
+ }
+
+ acc.Construct(str_vect, strlen_vect, idx);
+ delete[] str_vect;
+ delete[] strlen_vect;
+
+ // Step 2: convert to fast version
+ AC_Converter cvt(acc, ba);
+ return cvt.Convert() != 0;
+}
+
+static ac_result_t
+_match_helper(buf_header_t* ac, const char *str, unsigned int len) {
+ AC_Buffer* buf = (AC_Buffer*)(void*)ac;
+ ASSERT(ac->magic_num == AC_MAGIC_NUM);
+
+ ac_result_t r = Match(buf, str, len);
+ return r;
+}
+
+// LUA sematic:
+// input: array of strings
+// output: userdata containing the AC-graph (i.e. the AC_Buffer).
+//
+static int
+lac_create(lua_State* L) {
+ // The table of the array must be the 1st argument.
+ int input_tab = 1;
+
+ luaL_checktype(L, input_tab, LUA_TTABLE);
+
+ // Init the "iteartor".
+ lua_pushnil(L);
+
+ vector<const char*> str_v;
+ vector<unsigned int> strlen_v;
+
+ // Loop over the elements
+ while (lua_next(L, input_tab)) {
+ size_t str_len;
+ const char* s = luaL_checklstring(L, -1, &str_len);
+ str_v.push_back(s);
+ strlen_v.push_back(str_len);
+
+ // remove the value, but keep the key as the iterator.
+ lua_pop(L, 1);
+ }
+
+ // pop the nil value
+ lua_pop(L, 1);
+
+ if (_create_helper(L, str_v, strlen_v)) {
+ // The AC graph, as a userdata is already pushed to the stack, hence 1.
+ return 1;
+ }
+
+ return 0;
+}
+
+// LUA input:
+// arg1: the userdata, representing the AC graph, returned from l_create().
+// arg2: the string to be matched.
+//
+// LUA return:
+// if match, return index range of the match; otherwise nil is returned.
+//
+static int
+lac_match(lua_State* L) {
+ buf_header_t* ac = (buf_header_t*)lua_touserdata(L, 1);
+ if (!ac) {
+ luaL_checkudata(L, 1, tname);
+ return 0;
+ }
+
+ size_t len;
+ const char* str;
+ #if LUA_VERSION_NUM >= 502
+ str = luaL_tolstring(L, 2, &len);
+ #else
+ str = lua_tolstring(L, 2, &len);
+ #endif
+ if (!str) {
+ luaL_checkstring(L, 2);
+ return 0;
+ }
+
+ ac_result_t r = _match_helper(ac, str, len);
+ if (r.match_begin != -1) {
+ lua_pushinteger(L, r.match_begin);
+ lua_pushinteger(L, r.match_end);
+ return 2;
+ }
+
+ return 0;
+}
+
+static const struct luaL_Reg lib_funcs[] = {
+ { "create", lac_create },
+ { "match", lac_match },
+ {0, 0}
+};
+
+extern "C" int AC_EXPORT
+luaopen_ahocorasick(lua_State* L) {
+ luaL_newmetatable(L, tname);
+
+#if LUA_VERSION_NUM == 501
+ luaL_register(L, tname, lib_funcs);
+#elif LUA_VERSION_NUM >= 502
+ luaL_newlib(L, lib_funcs);
+#else
+ #error "Don't know how to do it right"
+#endif
+ return 1;
+}