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Working version of storing {k=v} style for instance tables and removing

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__indices.
This commit is contained in:
Bruce Hill 2018-06-05 15:44:00 -07:00
parent 898f92d20a
commit 2320f87324
1 changed files with 89 additions and 131 deletions
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220
limmutable.c
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@ -19,7 +19,6 @@
* hash buckets: weak-keyed map from instance userdata -> table of values
* __buckets: weak-keyed map from instance userdata -> hash bucket (used to manage hash bucket lifetimes)
* __fields: list of named fields
* __indices: map from field names to the index in the instance table where the value is stored
* metamethods, methods, class variables, etc.
*/
@ -50,11 +49,11 @@ static int WEAK_VALUE_METATABLE;
// constructed classes to have the same metatable:
// {__new=Lcreate_instance, __tostring=function(cls) return cls.name or 'immutable(...)' end}
static int SHARED_CLASS_METATABLE;
static int SUPER_METHODS;
static int SUPER_METHODS, NIL_SENTINEL;
typedef struct {
int hash;
size_t len;
size_t array_len;
} immutable_info_t;
#define IMMUTABLE_GETVALUE(i) if (from_table) {\
@ -68,8 +67,12 @@ typedef struct {
if (i <= num_args) {\
lua_pushvalue(L, 1+i);\
} else {\
lua_pushnil(L);\
lua_pushlightuserdata(L, &NIL_SENTINEL);\
}\
}\
if (lua_isnil(L, -1)) {\
lua_pop(L, 1);\
lua_pushlightuserdata(L, &NIL_SENTINEL);\
}
static inline int _create_instance(lua_State *L, int from_table)
@ -79,6 +82,7 @@ static inline int _create_instance(lua_State *L, int from_table)
int fields_index = lua_gettop(L);
size_t num_fields = lua_objlen(L, -1);
size_t num_values = from_table ? (num_fields + lua_objlen(L, 2)) : (num_args >= num_fields ? num_args : num_fields);
size_t array_len = num_values - num_fields;
// Compute the hash and populate the values table:
// Stack: [fields]
@ -107,11 +111,15 @@ static inline int _create_instance(lua_State *L, int from_table)
// Arbitrarily chosen values
item_hash = lua_toboolean(L, -1)? 0x82684f71 : 0x88d66f2a;
break;
case LUA_TLIGHTUSERDATA:
if (lua_touserdata(L, -1) == &NIL_SENTINEL) {
item_hash = (1000003 * type) ^ (lua_Integer)lua_topointer(L, -1);
break;
}
case LUA_TTABLE:
case LUA_TFUNCTION:
case LUA_TUSERDATA:
case LUA_TTHREAD:
case LUA_TLIGHTUSERDATA:
item_hash = (1000003 * type) ^ (lua_Integer)lua_topointer(L, -1);
break;
case LUA_TSTRING:
@ -163,12 +171,14 @@ static inline int _create_instance(lua_State *L, int from_table)
// Stack: [fields, __instances, bucket, hash_collider_inst, collider_table]
// Shallow equality check:
immutable_info_t *collider_info = (immutable_info_t*)lua_touserdata(L, -2);
if (collider_info->len != num_values) {
if (collider_info->array_len != array_len) {
lua_pop(L, 1);
goto next_bucket_item;
}
for (size_t i = 1; i <= num_values; i++) {
lua_rawgeti(L, -1, i);
// Stack: [fields, __instances, bucket, hash_collider_inst, collider_table]
for (size_t i = 1; i <= num_fields; i++) {
lua_rawgeti(L, fields_index, i);
lua_gettable(L, -2);
IMMUTABLE_GETVALUE(i);
// Stack: [fields, __instances, bucket, hash_collider_inst, collider_table, collider_val, inst_val]
if (! lua_rawequal(L, -1, -2)) { // If the i'th entry doesn't match the i'th arg
@ -178,6 +188,17 @@ static inline int _create_instance(lua_State *L, int from_table)
lua_pop(L, 2);
}
}
for (size_t i = 1; i <= array_len; i++) {
lua_rawgeti(L, -1, i);
IMMUTABLE_GETVALUE(i+num_fields);
// Stack: [fields, __instances, bucket, hash_collider_inst, collider_table, collider_val, inst_val]
if (! lua_rawequal(L, -1, -2)) { // If the i'th entry doesn't match the i'th arg
lua_pop(L, 3);
goto next_bucket_item;
} else {
lua_pop(L, 2);
}
}
// bucket item matches
// Stack: [fields, __instances, bucket, hash_collider_inst, collider_table]
lua_pop(L, 1);
@ -194,7 +215,7 @@ static inline int _create_instance(lua_State *L, int from_table)
// Stack: [fields, __instances, bucket, inst_userdata]
int userdata_index = lua_gettop(L);
userdata->hash = hash;
userdata->len = num_values;
userdata->array_len = array_len;
lua_pushvalue(L, 1);
// Stack: [fields, __instances, bucket, inst_userdata, cls]
@ -214,9 +235,14 @@ static inline int _create_instance(lua_State *L, int from_table)
lua_pushvalue(L, userdata_index);
// Stack: [fields, __instances, bucket, inst_userdata, inst_userdata]
lua_createtable(L, num_values, 0);
for (size_t i=1; i <= num_values; i++) {
lua_createtable(L, num_values-num_fields, num_fields);
for (size_t i=1; i <= num_fields; i++) {
lua_rawgeti(L, fields_index, i);
IMMUTABLE_GETVALUE(i);
lua_settable(L, -3);
}
for (size_t i=1; i <= array_len; i++) {
IMMUTABLE_GETVALUE(i+num_fields);
lua_rawseti(L, -2, i);
}
// Stack: [fields, __instances, bucket, inst_userdata, inst_userdata, inst_table]
@ -263,49 +289,24 @@ static int Llen(lua_State *L)
luaL_error(L, "invalid type");
}
immutable_info_t *info = (immutable_info_t *)lua_touserdata(L, 1);
lua_getfield(L, -1, "__fields");
size_t len = info->len - lua_objlen(L, -1);
lua_pushinteger(L, len);
lua_pushinteger(L, info->array_len);
return 1;
}
static int Linst_index(lua_State *L)
static int Lindex(lua_State *L)
{
// Return inst[key], <whether inst has key>
luaL_checktype(L, 1, LUA_TUSERDATA);
if (! lua_getmetatable(L, 1)) {
luaL_error(L, "invalid type");
}
int class_index = lua_gettop(L);
// Stack: [mt]
immutable_info_t *info = (immutable_info_t*)lua_touserdata(L, 1);
if (! info) {
luaL_error(L, "invalid type");
}
lua_getfield(L, -1, "__fields");
size_t num_fields = lua_objlen(L, -1);
lua_pop(L, 1);
// Stack: [mt]
lua_getfield(L, -1, "__indices");
// Stack: [mt, indices]
lua_pushvalue(L, 2);
lua_gettable(L, -2);
// Stack: [mt, indices, index]
int index;
if (lua_isnil(L, -1)) {
if (! lua_isinteger(L, 2)) {
return 0;
}
index = lua_tointeger(L, 2) + num_fields;
} else {
index = lua_tointeger(L, -1);
}
lua_pop(L, 2);
// Stack: [mt]
if (! (0 < index && index <= (int)info->len)) {
return 0;
}
// Stack: [mt]
lua_getfield(L, -1, "__instances");
// Stack: [mt, buckets]
@ -321,28 +322,20 @@ static int Linst_index(lua_State *L)
if (lua_isnil(L, -1)) {
luaL_error(L, "Failed to find instance");
}
lua_rawgeti(L, -1, index);
lua_pushboolean(L, 1);
return 2;
}
static int Lindex(lua_State *L)
{
int ret = Linst_index(L);
if (ret > 0) {
return ret;
}
// Fall back to class:
lua_getmetatable(L, 1);
// Stack: [..., mt]
lua_pushvalue(L, 2);
// Stack: [..., mt, key]
lua_gettable(L, -2);
// Stack: [..., mt, value]
if (! lua_isnil(L, -1)) {
if (lua_isnil(L, -1)) {
// Fall back to class:
lua_pushvalue(L, 2);
lua_gettable(L, class_index);
return 1;
}
return 0;
if (lua_islightuserdata(L, -1) && lua_touserdata(L, -1) == &NIL_SENTINEL) {
lua_pop(L, 1);
lua_pushnil(L);
}
lua_pushboolean(L, 1);
return 2;
}
static int Ltostring(lua_State *L)
@ -382,10 +375,13 @@ static int Ltostring(lua_State *L)
}
int inst_table_index = lua_gettop(L);
// Stack: [mt, buckets, bucket, inst_table]
lua_getfield(L, cls_index, "__fields");
int fields_index = lua_gettop(L);
lua_getglobal(L, "tostring");
int tostring_index = lua_gettop(L);
// Stack: [mt, buckets, bucket, inst_table, tostring]
int n = info->len, i = 1;
// Stack: [mt, buckets, bucket, inst_table, __fields, tostring]
int num_fields = lua_objlen(L, fields_index);
int n = num_fields + info->array_len, i = 1;
if (i <= n) {
goto first_list_item;
}
@ -395,7 +391,16 @@ static int Ltostring(lua_State *L)
first_list_item:
lua_pushvalue(L, tostring_index);
// Stack: [mt, buckets, bucket, inst_table, tostring, ???, tostring]
lua_rawgeti(L, inst_table_index, i);
if (i <= num_fields) {
lua_rawgeti(L, fields_index, i);
lua_gettable(L, inst_table_index);
} else {
lua_rawgeti(L, inst_table_index, i - num_fields);
}
if (lua_islightuserdata(L, -1) && lua_touserdata(L, -1) == &NIL_SENTINEL) {
lua_pop(L, 1);
lua_pushnil(L);
}
// Stack: [mt, buckets, bucket, inst_table, tostring, ???, tostring, value]
int quotes = lua_type(L, -1) == LUA_TSTRING;
lua_call(L, 1, 1);
@ -420,7 +425,6 @@ static int Lnexti(lua_State *L)
if (! lua_getmetatable(L, 1)) {
luaL_error(L, "invalid type");
}
int cls_index = lua_gettop(L);
// Stack: [mt]
lua_getfield(L, -1, "__instances");
// Stack: [mt, buckets]
@ -428,11 +432,8 @@ static int Lnexti(lua_State *L)
if (! info) {
luaL_error(L, "invalid type");
}
int i = lua_isnil(L, 2) ? 1 : lua_tointeger(L, 2)+1;
lua_getfield(L, cls_index, "__fields");
int num_fields = lua_objlen(L, -1);
lua_pop(L, 1);
if (i + num_fields > (int)info->len) {
int i = lua_tointeger(L, 2)+1;
if (i > (int)info->array_len) {
return 0;
}
lua_rawgeti(L, -1, info->hash);
@ -446,8 +447,12 @@ static int Lnexti(lua_State *L)
// Stack: [mt, buckets, bucket, inst_table]
lua_pushinteger(L, i);
// Stack: [mt, buckets, bucket, inst_table, i]
lua_rawgeti(L, -2, i + num_fields);
lua_rawgeti(L, -2, i);
// Stack: [mt, buckets, bucket, inst_table, i, table[i]]
if (lua_islightuserdata(L, -1) && lua_touserdata(L, -1) == &NIL_SENTINEL) {
lua_pop(L, 1);
lua_pushnil(L);
}
return 2;
}
@ -457,8 +462,8 @@ static int Lipairs(lua_State *L)
// Stack: [Lnexti]
lua_pushvalue(L, 1);
// Stack: [Lnexti, inst_udata]
lua_pushnil(L);
// Stack: [Lnexti, inst_udata, nil]
lua_pushinteger(L, 0);
// Stack: [Lnexti, inst_udata, 0]
return 3;
}
@ -467,57 +472,31 @@ static int Lnext(lua_State *L)
if (! lua_getmetatable(L, 1)) {
luaL_error(L, "invalid type");
}
int cls_index = lua_gettop(L);
// Stack: [mt]
lua_getfield(L, cls_index, "__fields");
int fields_index = lua_gettop(L);
lua_getfield(L, cls_index, "__indices");
int indices_index = lua_gettop(L);
lua_getfield(L, cls_index, "__instances");
// Stack: [..., buckets]
lua_getfield(L, -1, "__instances");
// Stack: [mt, buckets]
immutable_info_t *info = (immutable_info_t*)lua_touserdata(L, 1);
if (! info) {
luaL_error(L, "invalid type");
}
lua_rawgeti(L, -1, info->hash);
// Stack: [..., buckets, bucket]
// Stack: [mt, buckets, bucket]
if (lua_isnil(L, -1)) {
luaL_error(L, "Failed to find hash bucket");
}
lua_pushvalue(L, 1);
// Stack: [..., buckets, bucket, inst_udata]
// Stack: [mt, buckets, bucket, inst_udata]
lua_rawget(L, -2);
// Stack: [..., buckets, bucket, inst_table]
size_t num_fields = lua_objlen(L, fields_index);
int index;
if (lua_isnil(L, 2)) {
index = 1;
} else {
lua_pushvalue(L, 2);
// Stack: [..., buckets, bucket, inst_table, k]
lua_gettable(L, indices_index);
// Stack: [..., buckets, bucket, inst_table, i]
if (! lua_isnil(L, -1)) {
index = lua_tointeger(L, -1) + 1;
} else {
index = lua_tointeger(L, 2) + num_fields + 1;
}
lua_pop(L, 1);
}
// Stack: [..., buckets, bucket, inst_table]
if (! (0 < index && index <= (int)info->len)) {
// Stack: [mt, buckets, bucket, inst_table]
lua_pushvalue(L, 2);
// TODO: this is in a random order, and it might be good to force it to be in the same order as __fields
if (lua_next(L, -2) == 0) {
return 0;
}
// Now find field name
if (index <= (int)num_fields) {
lua_rawgeti(L, fields_index, index);
} else {
lua_pushinteger(L, index - num_fields);
if (lua_islightuserdata(L, -1) && lua_touserdata(L, -1) == &NIL_SENTINEL) {
lua_pop(L, 1);
lua_pushnil(L);
}
// Stack: [..., buckets, bucket, inst_table, k2]
lua_rawgeti(L, -2, index);
// Stack: [..., buckets, bucket, inst_table, k2, value2]
return 2;
}
@ -605,39 +584,18 @@ static int Lmake_class(lua_State *L)
// Stack: [CLS]
switch (num_args == 0 ? LUA_TNIL : lua_type(L, 1)) {
case LUA_TTABLE: {
// CLS.__fields = arg1
case LUA_TTABLE:
lua_pushvalue(L, 1);
// Stack: [CLS, __fields]
lua_setfield(L, -2, "__fields");
// Stack: [CLS]
size_t n = lua_objlen(L, 1);
lua_createtable(L, 0, n);
// Stack: [CLS, __indices]
lua_pushnil(L);
while (lua_next(L, 1) != 0) {
// Stack: [CLS, __indices, i, fieldname]
lua_pushvalue(L, -2);
// Stack: [CLS, __indices, i, fieldname, i]
lua_settable(L, -4);
// Stack: [CLS, __indices, i]
}
lua_setfield(L, -2, "__indices");
break;
}
case LUA_TNIL: case LUA_TNONE: {
// If no fields were passed in, set __fields and __indices to empty tables
case LUA_TNIL: case LUA_TNONE:
// If no fields were passed in, set __fields to empty table
lua_createtable(L, 0, 0);
lua_setfield(L, -2, "__fields");
lua_createtable(L, 0, 0);
lua_setfield(L, -2, "__indices");
break;
}
default: {
luaL_error(L, "immutable expected the fields to be either table or nil");
}
}
lua_setfield(L, -2, "__fields");
// Stack: [CLS]
lua_pushlightuserdata(L, (void*)&SHARED_CLASS_METATABLE);
lua_gettable(L, LUA_REGISTRYINDEX);