| 45 | **/ |
| 46 | template <class TStringType, typename TStringViewType = TBasicStringBuf<typename TStringType::value_type>> |
| 47 | static inline size_t SubstGlobalImpl(TStringType& s, const TStringViewType from, const TStringViewType to, size_t fromPos = 0) { |
| 48 | if (from.empty()) { |
| 49 | return 0; |
| 50 | } |
| 51 | |
| 52 | Y_ASSERT(!IsIntersect(s, from)); |
| 53 | Y_ASSERT(!IsIntersect(s, to)); |
| 54 | |
| 55 | const size_t fromSize = from.size(); |
| 56 | const size_t toSize = to.size(); |
| 57 | size_t replacementsCount = 0; |
| 58 | size_t off = fromPos; |
| 59 | size_t srcPos = 0; |
| 60 | |
| 61 | if (toSize > fromSize) { |
| 62 | // string will grow: append to another string |
| 63 | TStringType result; |
| 64 | for (; (off = TStringViewType(s).find(from, off)) != TStringType::npos; off += fromSize) { |
| 65 | if (!replacementsCount) { |
| 66 | // first replacement occured, we can prepare result string |
| 67 | result.reserve(s.size() + s.size() / 3); |
| 68 | } |
| 69 | result.append(s.begin() + srcPos, s.begin() + off); |
| 70 | result.append(to.data(), to.size()); |
| 71 | srcPos = off + fromSize; |
| 72 | ++replacementsCount; |
| 73 | } |
| 74 | if (replacementsCount) { |
| 75 | // append tail |
| 76 | result.append(s.begin() + srcPos, s.end()); |
| 77 | s = std::move(result); |
| 78 | } |
| 79 | return replacementsCount; |
| 80 | } |
| 81 | |
| 82 | // string will not grow: use inplace algo |
| 83 | size_t dstPos = 0; |
| 84 | typename TStringType::value_type* ptr = &*s.begin(); |
| 85 | for (; (off = TStringViewType(s).find(from, off)) != TStringType::npos; off += fromSize) { |
| 86 | Y_ASSERT(dstPos <= srcPos); |
| 87 | MoveBlock<TStringType, TStringViewType, true>(ptr, srcPos, dstPos, off, to, toSize); |
| 88 | srcPos = off + fromSize; |
| 89 | ++replacementsCount; |
| 90 | } |
| 91 | |
| 92 | if (replacementsCount) { |
| 93 | // append tail |
| 94 | MoveBlock<TStringType, TStringViewType, false>(ptr, srcPos, dstPos, s.size(), to, toSize); |
| 95 | s.resize(dstPos); |
| 96 | } |
| 97 | return replacementsCount; |
| 98 | } |
| 99 | |
| 100 | /// Replaces all occurences of the 'from' symbol in a string to the 'to' symbol. |
| 101 | template <class TStringType> |