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authorBjörn Gustavsson <[email protected]>2011-04-27 05:24:38 +0200
committerBjörn Gustavsson <[email protected]>2011-05-04 15:20:03 +0200
commit963843aad736997a66db8f8fdec6b3099373b742 (patch)
tree7489f4c8510cf80a254b7f8ff67c3233eb08f5d9 /erts/emulator/beam
parent73830b087d3a69611c97751156e9f1c61e1ce26a (diff)
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iolist_size/1: Fix truncation of result
iolist_size/1 would silently return a truncated result for iolists whose size exceeded the word size. For example: iolist(lists:duplicate(256, <<0:(1 bsl 24)/unit:8>>)). would return 0 (instead of 4294967296 or 1 bsl 32). Rewrite iolist_size/1 to accumulate the size in a bignum if necessary and result the correct result.
Diffstat (limited to 'erts/emulator/beam')
-rw-r--r--erts/emulator/beam/bif.c142
1 files changed, 134 insertions, 8 deletions
diff --git a/erts/emulator/beam/bif.c b/erts/emulator/beam/bif.c
index 6b1ce823cb..e886792ba7 100644
--- a/erts/emulator/beam/bif.c
+++ b/erts/emulator/beam/bif.c
@@ -2168,20 +2168,146 @@ BIF_RETTYPE tl_1(BIF_ALIST_1)
/**********************************************************************/
/* return the size of an I/O list */
-BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
+static Eterm
+accumulate(Eterm acc, Uint size)
{
- Sint size = io_list_len(BIF_ARG_1);
+ if (is_non_value(acc)) {
+ /*
+ * There is no pre-existing accumulator. Allocate a
+ * bignum buffer with one extra word to be used if
+ * the bignum grows in the future.
+ */
+ Eterm* hp = (Eterm *) erts_alloc(ERTS_ALC_T_TEMP_TERM,
+ (BIG_UINT_HEAP_SIZE+1) *
+ sizeof(Eterm));
+ return uint_to_big(size, hp);
+ } else {
+ Eterm* big;
+ int need_heap;
- if (size == -1) {
- BIF_ERROR(BIF_P, BADARG);
- } else if (IS_USMALL(0, (Uint) size)) {
- BIF_RET(make_small(size));
+ /*
+ * Add 'size' to 'acc' in place. There is always one
+ * extra word allocated in case the bignum grows by one word.
+ */
+ big = big_val(acc);
+ need_heap = BIG_NEED_SIZE(BIG_SIZE(big));
+ acc = big_plus_small(acc, size, big);
+ if (BIG_NEED_SIZE(big_size(acc)) > need_heap) {
+ /*
+ * The extra word has been consumed. Grow the
+ * allocation by one word.
+ */
+ big = (Eterm *) erts_realloc(ERTS_ALC_T_TEMP_TERM,
+ big_val(acc),
+ (need_heap+1) * sizeof(Eterm));
+ acc = make_big(big);
+ }
+ return acc;
+ }
+}
+
+static Eterm
+consolidate(Process* p, Eterm acc, Uint size)
+{
+ Eterm* hp;
+
+ if (is_non_value(acc)) {
+ return erts_make_integer(size, p);
} else {
- Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
- BIF_RET(uint_to_big(size, hp));
+ Eterm* big;
+ Uint sz;
+ Eterm res;
+
+ acc = accumulate(acc, size);
+ big = big_val(acc);
+ sz = BIG_NEED_SIZE(BIG_SIZE(big));
+ hp = HAlloc(p, sz);
+ res = make_big(hp);
+ while (sz--) {
+ *hp++ = *big++;
+ }
+ erts_free(ERTS_ALC_T_TEMP_TERM, (void *) big_val(acc));
+ return res;
}
}
+BIF_RETTYPE iolist_size_1(BIF_ALIST_1)
+{
+ Eterm obj, hd;
+ Eterm* objp;
+ Uint size = 0;
+ Uint cur_size;
+ Uint new_size;
+ Eterm acc = THE_NON_VALUE;
+ DECLARE_ESTACK(s);
+
+ obj = BIF_ARG_1;
+ goto L_again;
+
+ while (!ESTACK_ISEMPTY(s)) {
+ obj = ESTACK_POP(s);
+ L_again:
+ if (is_list(obj)) {
+ L_iter_list:
+ objp = list_val(obj);
+ hd = CAR(objp);
+ obj = CDR(objp);
+ /* Head */
+ if (is_byte(hd)) {
+ size++;
+ if (size == 0) {
+ acc = accumulate(acc, (Uint) -1);
+ size = 1;
+ }
+ } else if (is_binary(hd) && binary_bitsize(hd) == 0) {
+ cur_size = binary_size(hd);
+ if ((new_size = size + cur_size) >= size) {
+ size = new_size;
+ } else {
+ acc = accumulate(acc, size);
+ size = cur_size;
+ }
+ } else if (is_list(hd)) {
+ ESTACK_PUSH(s, obj);
+ obj = hd;
+ goto L_iter_list;
+ } else if (is_not_nil(hd)) {
+ goto L_type_error;
+ }
+ /* Tail */
+ if (is_list(obj)) {
+ goto L_iter_list;
+ } else if (is_binary(obj) && binary_bitsize(obj) == 0) {
+ cur_size = binary_size(obj);
+ if ((new_size = size + cur_size) >= size) {
+ size = new_size;
+ } else {
+ acc = accumulate(acc, size);
+ size = cur_size;
+ }
+ } else if (is_not_nil(obj)) {
+ goto L_type_error;
+ }
+ } else if (is_binary(obj) && binary_bitsize(obj) == 0) {
+ cur_size = binary_size(obj);
+ if ((new_size = size + cur_size) >= size) {
+ size = new_size;
+ } else {
+ acc = accumulate(acc, size);
+ size = cur_size;
+ }
+ } else if (is_not_nil(obj)) {
+ goto L_type_error;
+ }
+ }
+
+ DESTROY_ESTACK(s);
+ BIF_RET(consolidate(BIF_P, acc, size));
+
+ L_type_error:
+ DESTROY_ESTACK(s);
+ BIF_ERROR(BIF_P, BADARG);
+}
/**********************************************************************/