1 // Copyright 2019 Google LLC.
2 // Use of this source code is governed by a BSD-style license that can be found in the LICENSE file.
3
4 #include "modules/skplaintexteditor/include/stringslice.h"
5
6 #include <algorithm>
7 #include <cassert>
8 #include <cstdlib>
9 #include <cstring>
10
11 using namespace SkPlainTextEditor;
12
operator ()(void * t)13 void StringSlice::FreeWrapper::operator()(void* t) { std::free(t); }
14
StringSlice(StringSlice && that)15 StringSlice::StringSlice(StringSlice&& that)
16 : fPtr(std::move(that.fPtr))
17 , fLength(that.fLength)
18 , fCapacity(that.fCapacity)
19 {
20 that.fLength = 0;
21 that.fCapacity = 0;
22 }
23
operator =(StringSlice && that)24 StringSlice& StringSlice::operator=(StringSlice&& that) {
25 if (this != &that) {
26 this->~StringSlice();
27 new (this)StringSlice(std::move(that));
28 }
29 return *this;
30 }
31
operator =(const StringSlice & that)32 StringSlice& StringSlice::operator=(const StringSlice& that) {
33 if (this != &that) {
34 fLength = 0;
35 if (that.size() > 0) {
36 this->insert(0, that.begin(), that.size());
37 }
38 }
39 return *this;
40 }
41
insert(std::size_t offset,const char * text,std::size_t length)42 void StringSlice::insert(std::size_t offset, const char* text, std::size_t length) {
43 if (length) {
44 offset = std::min(fLength, offset);
45 this->reserve(fLength + length);
46 char* s = fPtr.get();
47 assert(s);
48 if (offset != fLength) {
49 std::memmove(s + offset + length, s + offset, fLength - offset);
50 }
51 if (text) {
52 std::memcpy(s + offset, text, length);
53 } else {
54 std::memset(s + offset, 0, length);
55 }
56 fLength += length;
57 }
58 }
59
remove(std::size_t offset,std::size_t length)60 void StringSlice::remove(std::size_t offset, std::size_t length) {
61 if (length && offset < fLength) {
62 length = std::min(length, fLength - offset);
63 assert(length > 0);
64 assert(length + offset <= fLength);
65 if (length + offset < fLength) {
66 char* s = fPtr.get();
67 assert(s);
68 std::memmove(s + offset, s + offset + length, fLength - (length + offset));
69 }
70 fLength -= length;
71 }
72 }
73
realloc(std::size_t size)74 void StringSlice::realloc(std::size_t size) {
75 // round up to multiple of (1 << kBits) bytes
76 static constexpr unsigned kBits = 4;
77 fCapacity = size ? (((size - 1) >> kBits) + 1) << kBits : 0;
78 assert(fCapacity % (1u << kBits) == 0);
79 assert(fCapacity >= size);
80 fPtr.reset((char*)std::realloc(fPtr.release(), fCapacity));
81 assert(fCapacity >= fLength);
82 }
83