1 /*
2 ** $Id: ltablib.c,v 1.65.1.2 2014/05/07 16:32:55 roberto Exp $
3 ** Library for Table Manipulation
4 ** See Copyright Notice in lua.h
5 */
6
7
8 #include <sys/zfs_context.h>
9
10 #define ltablib_c
11 #define LUA_LIB
12
13 #include "lua.h"
14
15 #include "lauxlib.h"
16 #include "lualib.h"
17
18
19 #define aux_getn(L,n) (luaL_checktype(L, n, LUA_TTABLE), luaL_len(L, n))
20
21
22
23 #if defined(LUA_COMPAT_MAXN)
maxn(lua_State * L)24 static int maxn (lua_State *L) {
25 lua_Number max = 0;
26 luaL_checktype(L, 1, LUA_TTABLE);
27 lua_pushnil(L); /* first key */
28 while (lua_next(L, 1)) {
29 lua_pop(L, 1); /* remove value */
30 if (lua_type(L, -1) == LUA_TNUMBER) {
31 lua_Number v = lua_tonumber(L, -1);
32 if (v > max) max = v;
33 }
34 }
35 lua_pushnumber(L, max);
36 return 1;
37 }
38 #endif
39
40
tinsert(lua_State * L)41 static int tinsert (lua_State *L) {
42 int e = aux_getn(L, 1) + 1; /* first empty element */
43 int pos; /* where to insert new element */
44 switch (lua_gettop(L)) {
45 case 2: { /* called with only 2 arguments */
46 pos = e; /* insert new element at the end */
47 break;
48 }
49 case 3: {
50 int i;
51 pos = luaL_checkint(L, 2); /* 2nd argument is the position */
52 luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds");
53 for (i = e; i > pos; i--) { /* move up elements */
54 lua_rawgeti(L, 1, i-1);
55 lua_rawseti(L, 1, i); /* t[i] = t[i-1] */
56 }
57 break;
58 }
59 default: {
60 return luaL_error(L, "wrong number of arguments to " LUA_QL("insert"));
61 }
62 }
63 lua_rawseti(L, 1, pos); /* t[pos] = v */
64 return 0;
65 }
66
67
tremove(lua_State * L)68 static int tremove (lua_State *L) {
69 int size = aux_getn(L, 1);
70 int pos = luaL_optint(L, 2, size);
71 if (pos != size) /* validate 'pos' if given */
72 luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds");
73 lua_rawgeti(L, 1, pos); /* result = t[pos] */
74 for ( ; pos < size; pos++) {
75 lua_rawgeti(L, 1, pos+1);
76 lua_rawseti(L, 1, pos); /* t[pos] = t[pos+1] */
77 }
78 lua_pushnil(L);
79 lua_rawseti(L, 1, pos); /* t[pos] = nil */
80 return 1;
81 }
82
83
addfield(lua_State * L,luaL_Buffer * b,int i)84 static void addfield (lua_State *L, luaL_Buffer *b, int i) {
85 lua_rawgeti(L, 1, i);
86 if (!lua_isstring(L, -1))
87 luaL_error(L, "invalid value (%s) at index %d in table for "
88 LUA_QL("concat"), luaL_typename(L, -1), i);
89 luaL_addvalue(b);
90 }
91
92
tconcat(lua_State * L)93 static int tconcat (lua_State *L) {
94 luaL_Buffer b;
95 size_t lsep;
96 int i, last;
97 const char *sep = luaL_optlstring(L, 2, "", &lsep);
98 luaL_checktype(L, 1, LUA_TTABLE);
99 i = luaL_optint(L, 3, 1);
100 last = luaL_opt(L, luaL_checkint, 4, luaL_len(L, 1));
101 luaL_buffinit(L, &b);
102 for (; i < last; i++) {
103 addfield(L, &b, i);
104 luaL_addlstring(&b, sep, lsep);
105 }
106 if (i == last) /* add last value (if interval was not empty) */
107 addfield(L, &b, i);
108 luaL_pushresult(&b);
109 return 1;
110 }
111
112
113 /*
114 ** {======================================================
115 ** Pack/unpack
116 ** =======================================================
117 */
118
pack(lua_State * L)119 static int pack (lua_State *L) {
120 int n = lua_gettop(L); /* number of elements to pack */
121 lua_createtable(L, n, 1); /* create result table */
122 lua_pushinteger(L, n);
123 lua_setfield(L, -2, "n"); /* t.n = number of elements */
124 if (n > 0) { /* at least one element? */
125 int i;
126 lua_pushvalue(L, 1);
127 lua_rawseti(L, -2, 1); /* insert first element */
128 lua_replace(L, 1); /* move table into index 1 */
129 for (i = n; i >= 2; i--) /* assign other elements */
130 lua_rawseti(L, 1, i);
131 }
132 return 1; /* return table */
133 }
134
135
unpack(lua_State * L)136 static int unpack (lua_State *L) {
137 int i, e;
138 unsigned int n;
139 luaL_checktype(L, 1, LUA_TTABLE);
140 i = luaL_optint(L, 2, 1);
141 e = luaL_opt(L, luaL_checkint, 3, luaL_len(L, 1));
142 if (i > e) return 0; /* empty range */
143 n = (unsigned int)e - (unsigned int)i; /* number of elements minus 1 */
144 if (n > (INT_MAX - 10) || !lua_checkstack(L, ++n))
145 return luaL_error(L, "too many results to unpack");
146 lua_rawgeti(L, 1, i); /* push arg[i] (avoiding overflow problems) */
147 while (i++ < e) /* push arg[i + 1...e] */
148 lua_rawgeti(L, 1, i);
149 return n;
150 }
151
152 /* }====================================================== */
153
154
155
156 /*
157 ** {======================================================
158 ** Quicksort
159 ** (based on `Algorithms in MODULA-3', Robert Sedgewick;
160 ** Addison-Wesley, 1993.)
161 ** =======================================================
162 */
163
164
set2(lua_State * L,int i,int j)165 static void set2 (lua_State *L, int i, int j) {
166 lua_rawseti(L, 1, i);
167 lua_rawseti(L, 1, j);
168 }
169
sort_comp(lua_State * L,int a,int b)170 static int sort_comp (lua_State *L, int a, int b) {
171 if (!lua_isnil(L, 2)) { /* function? */
172 int res;
173 lua_pushvalue(L, 2);
174 lua_pushvalue(L, a-1); /* -1 to compensate function */
175 lua_pushvalue(L, b-2); /* -2 to compensate function and `a' */
176 lua_call(L, 2, 1);
177 res = lua_toboolean(L, -1);
178 lua_pop(L, 1);
179 return res;
180 }
181 else /* a < b? */
182 return lua_compare(L, a, b, LUA_OPLT);
183 }
184
auxsort(lua_State * L,int l,int u)185 static void auxsort (lua_State *L, int l, int u) {
186 while (l < u) { /* for tail recursion */
187 int i, j;
188 /* sort elements a[l], a[(l+u)/2] and a[u] */
189 lua_rawgeti(L, 1, l);
190 lua_rawgeti(L, 1, u);
191 if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */
192 set2(L, l, u); /* swap a[l] - a[u] */
193 else
194 lua_pop(L, 2);
195 if (u-l == 1) break; /* only 2 elements */
196 i = (l+u)/2;
197 lua_rawgeti(L, 1, i);
198 lua_rawgeti(L, 1, l);
199 if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */
200 set2(L, i, l);
201 else {
202 lua_pop(L, 1); /* remove a[l] */
203 lua_rawgeti(L, 1, u);
204 if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */
205 set2(L, i, u);
206 else
207 lua_pop(L, 2);
208 }
209 if (u-l == 2) break; /* only 3 elements */
210 lua_rawgeti(L, 1, i); /* Pivot */
211 lua_pushvalue(L, -1);
212 lua_rawgeti(L, 1, u-1);
213 set2(L, i, u-1);
214 /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */
215 i = l; j = u-1;
216 for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */
217 /* repeat ++i until a[i] >= P */
218 while (lua_rawgeti(L, 1, ++i), sort_comp(L, -1, -2)) {
219 if (i>=u) luaL_error(L, "invalid order function for sorting");
220 lua_pop(L, 1); /* remove a[i] */
221 }
222 /* repeat --j until a[j] <= P */
223 while (lua_rawgeti(L, 1, --j), sort_comp(L, -3, -1)) {
224 if (j<=l) luaL_error(L, "invalid order function for sorting");
225 lua_pop(L, 1); /* remove a[j] */
226 }
227 if (j<i) {
228 lua_pop(L, 3); /* pop pivot, a[i], a[j] */
229 break;
230 }
231 set2(L, i, j);
232 }
233 lua_rawgeti(L, 1, u-1);
234 lua_rawgeti(L, 1, i);
235 set2(L, u-1, i); /* swap pivot (a[u-1]) with a[i] */
236 /* a[l..i-1] <= a[i] == P <= a[i+1..u] */
237 /* adjust so that smaller half is in [j..i] and larger one in [l..u] */
238 if (i-l < u-i) {
239 j=l; i=i-1; l=i+2;
240 }
241 else {
242 j=i+1; i=u; u=j-2;
243 }
244 auxsort(L, j, i); /* call recursively the smaller one */
245 } /* repeat the routine for the larger one */
246 }
247
sort(lua_State * L)248 static int sort (lua_State *L) {
249 int n = aux_getn(L, 1);
250 luaL_checkstack(L, 40, ""); /* assume array is smaller than 2^40 */
251 if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */
252 luaL_checktype(L, 2, LUA_TFUNCTION);
253 lua_settop(L, 2); /* make sure there is two arguments */
254 auxsort(L, 1, n);
255 return 0;
256 }
257
258 /* }====================================================== */
259
260
261 static const luaL_Reg tab_funcs[] = {
262 {"concat", tconcat},
263 #if defined(LUA_COMPAT_MAXN)
264 {"maxn", maxn},
265 #endif
266 {"insert", tinsert},
267 {"pack", pack},
268 {"unpack", unpack},
269 {"remove", tremove},
270 {"sort", sort},
271 {NULL, NULL}
272 };
273
274
luaopen_table(lua_State * L)275 LUAMOD_API int luaopen_table (lua_State *L) {
276 luaL_newlib(L, tab_funcs);
277 #if defined(LUA_COMPAT_UNPACK)
278 /* _G.unpack = table.unpack */
279 lua_getfield(L, -1, "unpack");
280 lua_setglobal(L, "unpack");
281 #endif
282 return 1;
283 }
284
285