Loading changes/bug7191 0 → 100644 +3 −0 Original line number Diff line number Diff line o Bugfixes - The smartlist_bsearch_idx() function was broken for lists of length zero or one; fix it. This fixes bug7191. src/common/container.c +90 −16 Original line number Diff line number Diff line Loading @@ -571,31 +571,105 @@ smartlist_bsearch_idx(const smartlist_t *sl, const void *key, int (*compare)(const void *key, const void **member), int *found_out) { int hi = smartlist_len(sl) - 1, lo = 0, cmp, mid; int hi, lo, cmp, mid, len; tor_assert(sl); tor_assert(compare); tor_assert(found_out); len = smartlist_len(sl); /* Check for the trivial case of a zero-length list */ if (len == 0) { *found_out = 0; /* We already know smartlist_len(sl) is 0 in this case */ return 0; } /* Okay, we have a real search to do */ tor_assert(len > 0); lo = 0; hi = len - 1; /* * These invariants are always true: * * For all i such that 0 <= i < lo, sl[i] < key * For all i such that hi < i <= len, sl[i] > key */ while (lo <= hi) { mid = (lo + hi) / 2; cmp = compare(key, (const void**) &(sl->list[mid])); if (cmp>0) { /* key > sl[mid] */ lo = mid+1; } else if (cmp<0) { /* key < sl[mid] */ hi = mid-1; } else { /* key == sl[mid] */ if (cmp == 0) { /* sl[mid] == key; we found it */ *found_out = 1; return mid; } else if (cmp > 0) { /* * key > sl[mid] and an index i such that sl[i] == key must * have i > mid if it exists. */ /* Check for end-of-list case */ if (mid < len) { /* Normal case, move lo to the element immediately after sl[mid] */ lo = mid + 1; } else { /* These should always be true in this case */ tor_assert(mid == hi); tor_assert(mid == len); /* * We were at the end of the list and concluded that every element e * compares e < key. */ *found_out = 0; return len; } } else { /* This should always be true in this case */ tor_assert(cmp < 0); /* * key < sl[mid] and an index i such that sl[i] == key must * have i < mid if it exists. */ if (mid > 0) { /* Normal case, move hi to the element immediately before sl[mid] */ hi = mid - 1; } else { /* These should always be true in this case */ tor_assert(mid == lo); tor_assert(mid == 0); /* * We were at the beginning of the list and concluded that every * element e compares e > key. */ *found_out = 0; return 0; } /* lo > hi. */ { } } /* * lo > hi; we have no element matching key but we have elements falling * on both sides of it. The lo index points to the first element > key. */ tor_assert(lo == hi + 1); /* All other cases should have been handled */ tor_assert(lo >= 0); if (lo < smartlist_len(sl)) { tor_assert(lo <= len); tor_assert(hi >= 0); tor_assert(hi <= len); if (lo < len) { cmp = compare(key, (const void **) &(sl->list[lo])); tor_assert(cmp < 0); } else if (smartlist_len(sl)) { cmp = compare(key, (const void**) &(sl->list[smartlist_len(sl)-1])); } else { cmp = compare(key, (const void **) &(sl->list[len-1])); tor_assert(cmp > 0); } } *found_out = 0; return lo; } Loading Loading
changes/bug7191 0 → 100644 +3 −0 Original line number Diff line number Diff line o Bugfixes - The smartlist_bsearch_idx() function was broken for lists of length zero or one; fix it. This fixes bug7191.
src/common/container.c +90 −16 Original line number Diff line number Diff line Loading @@ -571,31 +571,105 @@ smartlist_bsearch_idx(const smartlist_t *sl, const void *key, int (*compare)(const void *key, const void **member), int *found_out) { int hi = smartlist_len(sl) - 1, lo = 0, cmp, mid; int hi, lo, cmp, mid, len; tor_assert(sl); tor_assert(compare); tor_assert(found_out); len = smartlist_len(sl); /* Check for the trivial case of a zero-length list */ if (len == 0) { *found_out = 0; /* We already know smartlist_len(sl) is 0 in this case */ return 0; } /* Okay, we have a real search to do */ tor_assert(len > 0); lo = 0; hi = len - 1; /* * These invariants are always true: * * For all i such that 0 <= i < lo, sl[i] < key * For all i such that hi < i <= len, sl[i] > key */ while (lo <= hi) { mid = (lo + hi) / 2; cmp = compare(key, (const void**) &(sl->list[mid])); if (cmp>0) { /* key > sl[mid] */ lo = mid+1; } else if (cmp<0) { /* key < sl[mid] */ hi = mid-1; } else { /* key == sl[mid] */ if (cmp == 0) { /* sl[mid] == key; we found it */ *found_out = 1; return mid; } else if (cmp > 0) { /* * key > sl[mid] and an index i such that sl[i] == key must * have i > mid if it exists. */ /* Check for end-of-list case */ if (mid < len) { /* Normal case, move lo to the element immediately after sl[mid] */ lo = mid + 1; } else { /* These should always be true in this case */ tor_assert(mid == hi); tor_assert(mid == len); /* * We were at the end of the list and concluded that every element e * compares e < key. */ *found_out = 0; return len; } } else { /* This should always be true in this case */ tor_assert(cmp < 0); /* * key < sl[mid] and an index i such that sl[i] == key must * have i < mid if it exists. */ if (mid > 0) { /* Normal case, move hi to the element immediately before sl[mid] */ hi = mid - 1; } else { /* These should always be true in this case */ tor_assert(mid == lo); tor_assert(mid == 0); /* * We were at the beginning of the list and concluded that every * element e compares e > key. */ *found_out = 0; return 0; } /* lo > hi. */ { } } /* * lo > hi; we have no element matching key but we have elements falling * on both sides of it. The lo index points to the first element > key. */ tor_assert(lo == hi + 1); /* All other cases should have been handled */ tor_assert(lo >= 0); if (lo < smartlist_len(sl)) { tor_assert(lo <= len); tor_assert(hi >= 0); tor_assert(hi <= len); if (lo < len) { cmp = compare(key, (const void **) &(sl->list[lo])); tor_assert(cmp < 0); } else if (smartlist_len(sl)) { cmp = compare(key, (const void**) &(sl->list[smartlist_len(sl)-1])); } else { cmp = compare(key, (const void **) &(sl->list[len-1])); tor_assert(cmp > 0); } } *found_out = 0; return lo; } Loading
