The Tor Browser / file comparison
comparison: xpcom/ds/StringBuilder.h
xpcom/ds/StringBuilder.h
- branch
- TOR_BUG_3246
- changeset 7
- 129ffea94266
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| -1:000000000000 | 0:9e127fba036a |
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| 1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */ | |
| 2 /* vim:set ts=4 sw=4 sts=4 et cindent: */ | |
| 3 /* This Source Code Form is subject to the terms of the Mozilla Public | |
| 4 * License, v. 2.0. If a copy of the MPL was not distributed with this | |
| 5 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ | |
| 6 | |
| 7 /* We would use std::max but MS makes it painful | |
| 8 // windef.h defines min and max macros that we don't want | |
| 9 // http://support.microsoft.com/kb/143208 | |
| 10 #ifdef _WIN32 | |
| 11 #define NOMINMAX | |
| 12 #endif | |
| 13 */ | |
| 14 | |
| 15 #include <stdlib.h> | |
| 16 #include <string.h> | |
| 17 #include "nsAlgorithm.h" | |
| 18 | |
| 19 /* This is a standard string builder like ones in Java | |
| 20 or C#. It uses a doubling allocation strategy | |
| 21 to grow when out of capacity. | |
| 22 | |
| 23 This does not use nsTArray because nsTArray starts | |
| 24 growing by multiples of page size after it is the | |
| 25 size of one page. We want to keep doubling in size | |
| 26 so that we can continue to append at high speed even | |
| 27 for large strings. | |
| 28 | |
| 29 Eventually, this should be templated for wide characters. | |
| 30 | |
| 31 */ | |
| 32 | |
| 33 namespace mozilla { | |
| 34 | |
| 35 class StringBuilder | |
| 36 { | |
| 37 public: | |
| 38 StringBuilder() { | |
| 39 mCapacity = 16; | |
| 40 mLength = 0; | |
| 41 mBuffer = static_cast<char*>(malloc(sizeof(char)*mCapacity)); | |
| 42 mBuffer[0] = '\0'; | |
| 43 } | |
| 44 | |
| 45 void Append(const char *s) { | |
| 46 size_t newLength = strlen(s); | |
| 47 | |
| 48 EnsureCapacity(mLength + newLength+1); | |
| 49 | |
| 50 // copy the entire string including the null terminator | |
| 51 memcpy(&mBuffer[mLength], s, newLength+1); | |
| 52 mLength += newLength; | |
| 53 } | |
| 54 | |
| 55 char *Buffer() { | |
| 56 return mBuffer; | |
| 57 } | |
| 58 | |
| 59 size_t Length() { | |
| 60 return mLength; | |
| 61 } | |
| 62 | |
| 63 size_t EnsureCapacity(size_t capacity) { | |
| 64 if (capacity > mCapacity) { | |
| 65 // make sure we at least double in size | |
| 66 mCapacity = XPCOM_MAX(capacity, mCapacity*2); | |
| 67 mBuffer = static_cast<char*>(realloc(mBuffer, mCapacity)); | |
| 68 mCapacity = moz_malloc_usable_size(mBuffer); | |
| 69 } | |
| 70 return mCapacity; | |
| 71 } | |
| 72 | |
| 73 ~StringBuilder() | |
| 74 { | |
| 75 free(mBuffer); | |
| 76 } | |
| 77 | |
| 78 private: | |
| 79 char *mBuffer; | |
| 80 size_t mLength; // the length of the contained string not including the null terminator | |
| 81 size_t mCapacity; // the total size of mBuffer | |
| 82 }; | |
| 83 | |
| 84 } |
