1 // © 2016 and later: Unicode, Inc. and others.
2 // License & terms of use: http://www.unicode.org/copyright.html
3 // Copyright (C) 2009-2013, International Business Machines
4 // Corporation and others. All Rights Reserved.
5 //
6 // Copyright 2004 and onwards Google Inc.
7 //
8 // Author: wilsonh@google.com (Wilson Hsieh)
9 //
10
11 #include "unicode/utypes.h"
12 #include "unicode/stringpiece.h"
13 #include "cstring.h"
14 #include "cmemory.h"
15
16 U_NAMESPACE_BEGIN
17
StringPiece(const char * str)18 StringPiece::StringPiece(const char* str)
19 : ptr_(str), length_((str == NULL) ? 0 : static_cast<int32_t>(uprv_strlen(str))) { }
20
StringPiece(const StringPiece & x,int32_t pos)21 StringPiece::StringPiece(const StringPiece& x, int32_t pos) {
22 if (pos < 0) {
23 pos = 0;
24 } else if (pos > x.length_) {
25 pos = x.length_;
26 }
27 ptr_ = x.ptr_ + pos;
28 length_ = x.length_ - pos;
29 }
30
StringPiece(const StringPiece & x,int32_t pos,int32_t len)31 StringPiece::StringPiece(const StringPiece& x, int32_t pos, int32_t len) {
32 if (pos < 0) {
33 pos = 0;
34 } else if (pos > x.length_) {
35 pos = x.length_;
36 }
37 if (len < 0) {
38 len = 0;
39 } else if (len > x.length_ - pos) {
40 len = x.length_ - pos;
41 }
42 ptr_ = x.ptr_ + pos;
43 length_ = len;
44 }
45
set(const char * str)46 void StringPiece::set(const char* str) {
47 ptr_ = str;
48 if (str != NULL)
49 length_ = static_cast<int32_t>(uprv_strlen(str));
50 else
51 length_ = 0;
52 }
53
54 U_EXPORT UBool U_EXPORT2
operator ==(const StringPiece & x,const StringPiece & y)55 operator==(const StringPiece& x, const StringPiece& y) {
56 int32_t len = x.size();
57 if (len != y.size()) {
58 return false;
59 }
60 if (len == 0) {
61 return true;
62 }
63 const char* p = x.data();
64 const char* p2 = y.data();
65 // Test last byte in case strings share large common prefix
66 --len;
67 if (p[len] != p2[len]) return false;
68 // At this point we can, but don't have to, ignore the last byte.
69 return uprv_memcmp(p, p2, len) == 0;
70 }
71
72
73 const int32_t StringPiece::npos = 0x7fffffff;
74
75 U_NAMESPACE_END
76