| // Copyright 2017 The Abseil Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "absl/strings/internal/memutil.h" |
| |
| #include <cstdlib> |
| |
| namespace absl { |
| namespace strings_internal { |
| |
| int memcasecmp(const char* s1, const char* s2, size_t len) { |
| const unsigned char* us1 = reinterpret_cast<const unsigned char*>(s1); |
| const unsigned char* us2 = reinterpret_cast<const unsigned char*>(s2); |
| |
| for (size_t i = 0; i < len; i++) { |
| const int diff = |
| int{static_cast<unsigned char>(absl::ascii_tolower(us1[i]))} - |
| int{static_cast<unsigned char>(absl::ascii_tolower(us2[i]))}; |
| if (diff != 0) return diff; |
| } |
| return 0; |
| } |
| |
| char* memdup(const char* s, size_t slen) { |
| void* copy; |
| if ((copy = malloc(slen)) == nullptr) return nullptr; |
| memcpy(copy, s, slen); |
| return reinterpret_cast<char*>(copy); |
| } |
| |
| char* memrchr(const char* s, int c, size_t slen) { |
| for (const char* e = s + slen - 1; e >= s; e--) { |
| if (*e == c) return const_cast<char*>(e); |
| } |
| return nullptr; |
| } |
| |
| size_t memspn(const char* s, size_t slen, const char* accept) { |
| const char* p = s; |
| const char* spanp; |
| char c, sc; |
| |
| cont: |
| c = *p++; |
| if (slen-- == 0) return p - 1 - s; |
| for (spanp = accept; (sc = *spanp++) != '\0';) |
| if (sc == c) goto cont; |
| return p - 1 - s; |
| } |
| |
| size_t memcspn(const char* s, size_t slen, const char* reject) { |
| const char* p = s; |
| const char* spanp; |
| char c, sc; |
| |
| while (slen-- != 0) { |
| c = *p++; |
| for (spanp = reject; (sc = *spanp++) != '\0';) |
| if (sc == c) return p - 1 - s; |
| } |
| return p - s; |
| } |
| |
| char* mempbrk(const char* s, size_t slen, const char* accept) { |
| const char* scanp; |
| int sc; |
| |
| for (; slen; ++s, --slen) { |
| for (scanp = accept; (sc = *scanp++) != '\0';) |
| if (sc == *s) return const_cast<char*>(s); |
| } |
| return nullptr; |
| } |
| |
| // This is significantly faster for case-sensitive matches with very |
| // few possible matches. See unit test for benchmarks. |
| const char* memmatch(const char* phaystack, size_t haylen, const char* pneedle, |
| size_t neelen) { |
| if (0 == neelen) { |
| return phaystack; // even if haylen is 0 |
| } |
| if (haylen < neelen) return nullptr; |
| |
| const char* match; |
| const char* hayend = phaystack + haylen - neelen + 1; |
| // A static cast is used here to work around the fact that memchr returns |
| // a void* on Posix-compliant systems and const void* on Windows. |
| while ((match = static_cast<const char*>( |
| memchr(phaystack, pneedle[0], hayend - phaystack)))) { |
| if (memcmp(match, pneedle, neelen) == 0) |
| return match; |
| else |
| phaystack = match + 1; |
| } |
| return nullptr; |
| } |
| |
| } // namespace strings_internal |
| } // namespace absl |