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authorRoberto Ierusalimschy <roberto@inf.puc-rio.br>2015-09-09 12:42:30 -0300
committerRoberto Ierusalimschy <roberto@inf.puc-rio.br>2015-09-09 12:42:30 -0300
commitbda83e22c0ab3e6fffbf0a71e5e4a5869da8f6ab (patch)
treec97128993d2c24d70f345863c6a3392f4e683de3 /ltablib.c
parent364cdbdbdbc1b5e88b1795460a09ea7f4a73a86b (diff)
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'tablib' does not try to use raw operations when possible: fast
track should make standard operations fast enough to forgo raw accesses
Diffstat (limited to 'ltablib.c')
-rw-r--r--ltablib.c165
1 files changed, 78 insertions, 87 deletions
diff --git a/ltablib.c b/ltablib.c
index af9bd9c6..a63b5351 100644
--- a/ltablib.c
+++ b/ltablib.c
@@ -1,5 +1,5 @@
1/* 1/*
2** $Id: ltablib.c,v 1.80 2015/01/13 16:27:29 roberto Exp roberto $ 2** $Id: ltablib.c,v 1.81 2015/07/04 16:31:42 roberto Exp roberto $
3** Library for Table Manipulation 3** Library for Table Manipulation
4** See Copyright Notice in lua.h 4** See Copyright Notice in lua.h
5*/ 5*/
@@ -19,42 +19,44 @@
19#include "lualib.h" 19#include "lualib.h"
20 20
21 21
22
23/* 22/*
24** Structure with table-access functions 23** Operations that an object must define to mimic a table
24** (some functions only need some of them)
25*/ 25*/
26typedef struct { 26#define TAB_R 1
27 int (*geti) (lua_State *L, int idx, lua_Integer n); 27#define TAB_W 2
28 void (*seti) (lua_State *L, int idx, lua_Integer n); 28#define TAB_L 4
29} TabA; 29#define TAB_RW (TAB_R | TAB_W)
30
31
32#define aux_getn(L,n,w) (checktab(L, n, (w) | TAB_L), luaL_len(L, n))
33
34
35static int checkfield (lua_State *L, const char *key, int n) {
36 lua_pushstring(L, key);
37 return (lua_rawget(L, -n) != LUA_TNIL);
38}
30 39
31 40
32/* 41/*
33** Check that 'arg' has a table and set access functions in 'ta' to raw 42** Check that 'arg' either is a table or can behave like one (that is,
34** or non-raw according to the presence of corresponding metamethods. 43** has a metatable with the required metamethods)
35*/ 44*/
36static void checktab (lua_State *L, int arg, TabA *ta) { 45static void checktab (lua_State *L, int arg, int what) {
37 ta->geti = NULL; ta->seti = NULL; 46 if (lua_type(L, arg) != LUA_TTABLE) { /* is it not a table? */
38 if (lua_getmetatable(L, arg)) { 47 int n = 1; /* number of elements to pop */
39 lua_pushliteral(L, "__index"); /* 'index' metamethod */ 48 if (lua_getmetatable(L, arg) && /* must have metatable */
40 if (lua_rawget(L, -2) != LUA_TNIL) 49 (!(what & TAB_R) || checkfield(L, "__index", ++n)) &&
41 ta->geti = lua_geti; 50 (!(what & TAB_W) || checkfield(L, "__newindex", ++n)) &&
42 lua_pushliteral(L, "__newindex"); /* 'newindex' metamethod */ 51 (!(what & TAB_L) || checkfield(L, "__len", ++n))) {
43 if (lua_rawget(L, -3) != LUA_TNIL) 52 lua_pop(L, n); /* pop metatable and tested metamethods */
44 ta->seti = lua_seti; 53}
45 lua_pop(L, 3); /* pop metatable plus both metamethods */ 54 else
46 } 55 luaL_argerror(L, arg, "table expected"); /* force an error */
47 if (ta->geti == NULL || ta->seti == NULL) {
48 luaL_checktype(L, arg, LUA_TTABLE); /* must be table for raw methods */
49 if (ta->geti == NULL) ta->geti = lua_rawgeti;
50 if (ta->seti == NULL) ta->seti = lua_rawseti;
51 } 56 }
52} 57}
53 58
54 59
55#define aux_getn(L,n,ta) (checktab(L, n, ta), luaL_len(L, n))
56
57
58#if defined(LUA_COMPAT_MAXN) 60#if defined(LUA_COMPAT_MAXN)
59static int maxn (lua_State *L) { 61static int maxn (lua_State *L) {
60 lua_Number max = 0; 62 lua_Number max = 0;
@@ -74,8 +76,7 @@ static int maxn (lua_State *L) {
74 76
75 77
76static int tinsert (lua_State *L) { 78static int tinsert (lua_State *L) {
77 TabA ta; 79 lua_Integer e = aux_getn(L, 1, TAB_RW) + 1; /* first empty element */
78 lua_Integer e = aux_getn(L, 1, &ta) + 1; /* first empty element */
79 lua_Integer pos; /* where to insert new element */ 80 lua_Integer pos; /* where to insert new element */
80 switch (lua_gettop(L)) { 81 switch (lua_gettop(L)) {
81 case 2: { /* called with only 2 arguments */ 82 case 2: { /* called with only 2 arguments */
@@ -87,8 +88,8 @@ static int tinsert (lua_State *L) {
87 pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */ 88 pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */
88 luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds"); 89 luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
89 for (i = e; i > pos; i--) { /* move up elements */ 90 for (i = e; i > pos; i--) { /* move up elements */
90 (*ta.geti)(L, 1, i - 1); 91 lua_geti(L, 1, i - 1);
91 (*ta.seti)(L, 1, i); /* t[i] = t[i - 1] */ 92 lua_seti(L, 1, i); /* t[i] = t[i - 1] */
92 } 93 }
93 break; 94 break;
94 } 95 }
@@ -96,42 +97,36 @@ static int tinsert (lua_State *L) {
96 return luaL_error(L, "wrong number of arguments to 'insert'"); 97 return luaL_error(L, "wrong number of arguments to 'insert'");
97 } 98 }
98 } 99 }
99 (*ta.seti)(L, 1, pos); /* t[pos] = v */ 100 lua_seti(L, 1, pos); /* t[pos] = v */
100 return 0; 101 return 0;
101} 102}
102 103
103 104
104static int tremove (lua_State *L) { 105static int tremove (lua_State *L) {
105 TabA ta; 106 lua_Integer size = aux_getn(L, 1, TAB_RW);
106 lua_Integer size = aux_getn(L, 1, &ta);
107 lua_Integer pos = luaL_optinteger(L, 2, size); 107 lua_Integer pos = luaL_optinteger(L, 2, size);
108 if (pos != size) /* validate 'pos' if given */ 108 if (pos != size) /* validate 'pos' if given */
109 luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds"); 109 luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
110 (*ta.geti)(L, 1, pos); /* result = t[pos] */ 110 lua_geti(L, 1, pos); /* result = t[pos] */
111 for ( ; pos < size; pos++) { 111 for ( ; pos < size; pos++) {
112 (*ta.geti)(L, 1, pos + 1); 112 lua_geti(L, 1, pos + 1);
113 (*ta.seti)(L, 1, pos); /* t[pos] = t[pos + 1] */ 113 lua_seti(L, 1, pos); /* t[pos] = t[pos + 1] */
114 } 114 }
115 lua_pushnil(L); 115 lua_pushnil(L);
116 (*ta.seti)(L, 1, pos); /* t[pos] = nil */ 116 lua_seti(L, 1, pos); /* t[pos] = nil */
117 return 1; 117 return 1;
118} 118}
119 119
120 120
121static int tmove (lua_State *L) { 121static int tmove (lua_State *L) {
122 TabA ta;
123 lua_Integer f = luaL_checkinteger(L, 2); 122 lua_Integer f = luaL_checkinteger(L, 2);
124 lua_Integer e = luaL_checkinteger(L, 3); 123 lua_Integer e = luaL_checkinteger(L, 3);
125 lua_Integer t = luaL_checkinteger(L, 4); 124 lua_Integer t = luaL_checkinteger(L, 4);
126 int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */ 125 int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */
126 checktab(L, 1, TAB_R);
127 checktab(L, tt, TAB_W);
127 if (e >= f) { /* otherwise, nothing to move */ 128 if (e >= f) { /* otherwise, nothing to move */
128 lua_Integer n, i; 129 lua_Integer n, i;
129 ta.geti = (luaL_getmetafield(L, 1, "__index") == LUA_TNIL)
130 ? (luaL_checktype(L, 1, LUA_TTABLE), lua_rawgeti)
131 : lua_geti;
132 ta.seti = (luaL_getmetafield(L, tt, "__newindex") == LUA_TNIL)
133 ? (luaL_checktype(L, tt, LUA_TTABLE), lua_rawseti)
134 : lua_seti;
135 luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3, 130 luaL_argcheck(L, f > 0 || e < LUA_MAXINTEGER + f, 3,
136 "too many elements to move"); 131 "too many elements to move");
137 n = e - f + 1; /* number of elements to move */ 132 n = e - f + 1; /* number of elements to move */
@@ -139,14 +134,14 @@ static int tmove (lua_State *L) {
139 "destination wrap around"); 134 "destination wrap around");
140 if (t > f) { 135 if (t > f) {
141 for (i = n - 1; i >= 0; i--) { 136 for (i = n - 1; i >= 0; i--) {
142 (*ta.geti)(L, 1, f + i); 137 lua_geti(L, 1, f + i);
143 (*ta.seti)(L, tt, t + i); 138 lua_seti(L, tt, t + i);
144 } 139 }
145 } 140 }
146 else { 141 else {
147 for (i = 0; i < n; i++) { 142 for (i = 0; i < n; i++) {
148 (*ta.geti)(L, 1, f + i); 143 lua_geti(L, 1, f + i);
149 (*ta.seti)(L, tt, t + i); 144 lua_seti(L, tt, t + i);
150 } 145 }
151 } 146 }
152 } 147 }
@@ -155,8 +150,8 @@ static int tmove (lua_State *L) {
155} 150}
156 151
157 152
158static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) { 153static void addfield (lua_State *L, luaL_Buffer *b, lua_Integer i) {
159 (*ta->geti)(L, 1, i); 154 lua_geti(L, 1, i);
160 if (!lua_isstring(L, -1)) 155 if (!lua_isstring(L, -1))
161 luaL_error(L, "invalid value (%s) at index %d in table for 'concat'", 156 luaL_error(L, "invalid value (%s) at index %d in table for 'concat'",
162 luaL_typename(L, -1), i); 157 luaL_typename(L, -1), i);
@@ -165,21 +160,20 @@ static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) {
165 160
166 161
167static int tconcat (lua_State *L) { 162static int tconcat (lua_State *L) {
168 TabA ta;
169 luaL_Buffer b; 163 luaL_Buffer b;
170 size_t lsep; 164 size_t lsep;
171 lua_Integer i, last; 165 lua_Integer i;
166 lua_Integer last = aux_getn(L, 1, TAB_R);
172 const char *sep = luaL_optlstring(L, 2, "", &lsep); 167 const char *sep = luaL_optlstring(L, 2, "", &lsep);
173 checktab(L, 1, &ta);
174 i = luaL_optinteger(L, 3, 1); 168 i = luaL_optinteger(L, 3, 1);
175 last = luaL_opt(L, luaL_checkinteger, 4, luaL_len(L, 1)); 169 last = luaL_opt(L, luaL_checkinteger, 4, last);
176 luaL_buffinit(L, &b); 170 luaL_buffinit(L, &b);
177 for (; i < last; i++) { 171 for (; i < last; i++) {
178 addfield(L, &b, &ta, i); 172 addfield(L, &b, i);
179 luaL_addlstring(&b, sep, lsep); 173 luaL_addlstring(&b, sep, lsep);
180 } 174 }
181 if (i == last) /* add last value (if interval was not empty) */ 175 if (i == last) /* add last value (if interval was not empty) */
182 addfield(L, &b, &ta, i); 176 addfield(L, &b, i);
183 luaL_pushresult(&b); 177 luaL_pushresult(&b);
184 return 1; 178 return 1;
185} 179}
@@ -197,7 +191,7 @@ static int pack (lua_State *L) {
197 lua_createtable(L, n, 1); /* create result table */ 191 lua_createtable(L, n, 1); /* create result table */
198 lua_insert(L, 1); /* put it at index 1 */ 192 lua_insert(L, 1); /* put it at index 1 */
199 for (i = n; i >= 1; i--) /* assign elements */ 193 for (i = n; i >= 1; i--) /* assign elements */
200 lua_rawseti(L, 1, i); 194 lua_seti(L, 1, i);
201 lua_pushinteger(L, n); 195 lua_pushinteger(L, n);
202 lua_setfield(L, 1, "n"); /* t.n = number of elements */ 196 lua_setfield(L, 1, "n"); /* t.n = number of elements */
203 return 1; /* return table */ 197 return 1; /* return table */
@@ -205,10 +199,8 @@ static int pack (lua_State *L) {
205 199
206 200
207static int unpack (lua_State *L) { 201static int unpack (lua_State *L) {
208 TabA ta;
209 lua_Integer i, e; 202 lua_Integer i, e;
210 lua_Unsigned n; 203 lua_Unsigned n;
211 checktab(L, 1, &ta);
212 i = luaL_optinteger(L, 2, 1); 204 i = luaL_optinteger(L, 2, 1);
213 e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1)); 205 e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1));
214 if (i > e) return 0; /* empty range */ 206 if (i > e) return 0; /* empty range */
@@ -216,9 +208,9 @@ static int unpack (lua_State *L) {
216 if (n >= (unsigned int)INT_MAX || !lua_checkstack(L, (int)(++n))) 208 if (n >= (unsigned int)INT_MAX || !lua_checkstack(L, (int)(++n)))
217 return luaL_error(L, "too many results to unpack"); 209 return luaL_error(L, "too many results to unpack");
218 for (; i < e; i++) { /* push arg[i..e - 1] (to avoid overflows) */ 210 for (; i < e; i++) { /* push arg[i..e - 1] (to avoid overflows) */
219 (*ta.geti)(L, 1, i); 211 lua_geti(L, 1, i);
220 } 212 }
221 (*ta.geti)(L, 1, e); /* push last element */ 213 lua_geti(L, 1, e); /* push last element */
222 return (int)n; 214 return (int)n;
223} 215}
224 216
@@ -235,9 +227,9 @@ static int unpack (lua_State *L) {
235*/ 227*/
236 228
237 229
238static void set2 (lua_State *L, TabA *ta, int i, int j) { 230static void set2 (lua_State *L, int i, int j) {
239 (*ta->seti)(L, 1, i); 231 lua_seti(L, 1, i);
240 (*ta->seti)(L, 1, j); 232 lua_seti(L, 1, j);
241} 233}
242 234
243static int sort_comp (lua_State *L, int a, int b) { 235static int sort_comp (lua_State *L, int a, int b) {
@@ -255,45 +247,45 @@ static int sort_comp (lua_State *L, int a, int b) {
255 return lua_compare(L, a, b, LUA_OPLT); 247 return lua_compare(L, a, b, LUA_OPLT);
256} 248}
257 249
258static void auxsort (lua_State *L, TabA *ta, int l, int u) { 250static void auxsort (lua_State *L, int l, int u) {
259 while (l < u) { /* for tail recursion */ 251 while (l < u) { /* for tail recursion */
260 int i, j; 252 int i, j;
261 /* sort elements a[l], a[(l+u)/2] and a[u] */ 253 /* sort elements a[l], a[(l+u)/2] and a[u] */
262 (*ta->geti)(L, 1, l); 254 lua_geti(L, 1, l);
263 (*ta->geti)(L, 1, u); 255 lua_geti(L, 1, u);
264 if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */ 256 if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */
265 set2(L, ta, l, u); /* swap a[l] - a[u] */ 257 set2(L, l, u); /* swap a[l] - a[u] */
266 else 258 else
267 lua_pop(L, 2); 259 lua_pop(L, 2);
268 if (u-l == 1) break; /* only 2 elements */ 260 if (u-l == 1) break; /* only 2 elements */
269 i = (l+u)/2; 261 i = (l+u)/2;
270 (*ta->geti)(L, 1, i); 262 lua_geti(L, 1, i);
271 (*ta->geti)(L, 1, l); 263 lua_geti(L, 1, l);
272 if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */ 264 if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */
273 set2(L, ta, i, l); 265 set2(L, i, l);
274 else { 266 else {
275 lua_pop(L, 1); /* remove a[l] */ 267 lua_pop(L, 1); /* remove a[l] */
276 (*ta->geti)(L, 1, u); 268 lua_geti(L, 1, u);
277 if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */ 269 if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */
278 set2(L, ta, i, u); 270 set2(L, i, u);
279 else 271 else
280 lua_pop(L, 2); 272 lua_pop(L, 2);
281 } 273 }
282 if (u-l == 2) break; /* only 3 elements */ 274 if (u-l == 2) break; /* only 3 elements */
283 (*ta->geti)(L, 1, i); /* Pivot */ 275 lua_geti(L, 1, i); /* Pivot */
284 lua_pushvalue(L, -1); 276 lua_pushvalue(L, -1);
285 (*ta->geti)(L, 1, u-1); 277 lua_geti(L, 1, u-1);
286 set2(L, ta, i, u-1); 278 set2(L, i, u-1);
287 /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */ 279 /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
288 i = l; j = u-1; 280 i = l; j = u-1;
289 for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */ 281 for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */
290 /* repeat ++i until a[i] >= P */ 282 /* repeat ++i until a[i] >= P */
291 while ((*ta->geti)(L, 1, ++i), sort_comp(L, -1, -2)) { 283 while (lua_geti(L, 1, ++i), sort_comp(L, -1, -2)) {
292 if (i>=u) luaL_error(L, "invalid order function for sorting"); 284 if (i>=u) luaL_error(L, "invalid order function for sorting");
293 lua_pop(L, 1); /* remove a[i] */ 285 lua_pop(L, 1); /* remove a[i] */
294 } 286 }
295 /* repeat --j until a[j] <= P */ 287 /* repeat --j until a[j] <= P */
296 while ((*ta->geti)(L, 1, --j), sort_comp(L, -3, -1)) { 288 while (lua_geti(L, 1, --j), sort_comp(L, -3, -1)) {
297 if (j<=l) luaL_error(L, "invalid order function for sorting"); 289 if (j<=l) luaL_error(L, "invalid order function for sorting");
298 lua_pop(L, 1); /* remove a[j] */ 290 lua_pop(L, 1); /* remove a[j] */
299 } 291 }
@@ -301,11 +293,11 @@ static void auxsort (lua_State *L, TabA *ta, int l, int u) {
301 lua_pop(L, 3); /* pop pivot, a[i], a[j] */ 293 lua_pop(L, 3); /* pop pivot, a[i], a[j] */
302 break; 294 break;
303 } 295 }
304 set2(L, ta, i, j); 296 set2(L, i, j);
305 } 297 }
306 (*ta->geti)(L, 1, u-1); 298 lua_geti(L, 1, u-1);
307 (*ta->geti)(L, 1, i); 299 lua_geti(L, 1, i);
308 set2(L, ta, u-1, i); /* swap pivot (a[u-1]) with a[i] */ 300 set2(L, u-1, i); /* swap pivot (a[u-1]) with a[i] */
309 /* a[l..i-1] <= a[i] == P <= a[i+1..u] */ 301 /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
310 /* adjust so that smaller half is in [j..i] and larger one in [l..u] */ 302 /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
311 if (i-l < u-i) { 303 if (i-l < u-i) {
@@ -314,18 +306,17 @@ static void auxsort (lua_State *L, TabA *ta, int l, int u) {
314 else { 306 else {
315 j=i+1; i=u; u=j-2; 307 j=i+1; i=u; u=j-2;
316 } 308 }
317 auxsort(L, ta, j, i); /* call recursively the smaller one */ 309 auxsort(L, j, i); /* call recursively the smaller one */
318 } /* repeat the routine for the larger one */ 310 } /* repeat the routine for the larger one */
319} 311}
320 312
321static int sort (lua_State *L) { 313static int sort (lua_State *L) {
322 TabA ta; 314 int n = (int)aux_getn(L, 1, TAB_RW);
323 int n = (int)aux_getn(L, 1, &ta);
324 luaL_checkstack(L, 50, ""); /* assume array is smaller than 2^50 */ 315 luaL_checkstack(L, 50, ""); /* assume array is smaller than 2^50 */
325 if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ 316 if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
326 luaL_checktype(L, 2, LUA_TFUNCTION); 317 luaL_checktype(L, 2, LUA_TFUNCTION);
327 lua_settop(L, 2); /* make sure there are two arguments */ 318 lua_settop(L, 2); /* make sure there are two arguments */
328 auxsort(L, &ta, 1, n); 319 auxsort(L, 1, n);
329 return 0; 320 return 0;
330} 321}
331 322