1// Copyright (C) 2009-2013, International Business Machines
2// Corporation and others. All Rights Reserved.
3//
4// Copyright 2004 and onwards Google Inc.
5//
6// Author: wilsonh@google.com (Wilson Hsieh)
7//
8
9#include "unicode/utypes.h"
10#include "unicode/stringpiece.h"
11#include "cstring.h"
12#include "cmemory.h"
13
14U_NAMESPACE_BEGIN
15
16StringPiece::StringPiece(const char* str)
17    : ptr_(str), length_((str == NULL) ? 0 : static_cast<int32_t>(uprv_strlen(str))) { }
18
19StringPiece::StringPiece(const StringPiece& x, int32_t pos) {
20  if (pos < 0) {
21    pos = 0;
22  } else if (pos > x.length_) {
23    pos = x.length_;
24  }
25  ptr_ = x.ptr_ + pos;
26  length_ = x.length_ - pos;
27}
28
29StringPiece::StringPiece(const StringPiece& x, int32_t pos, int32_t len) {
30  if (pos < 0) {
31    pos = 0;
32  } else if (pos > x.length_) {
33    pos = x.length_;
34  }
35  if (len < 0) {
36    len = 0;
37  } else if (len > x.length_ - pos) {
38    len = x.length_ - pos;
39  }
40  ptr_ = x.ptr_ + pos;
41  length_ = len;
42}
43
44void StringPiece::set(const char* str) {
45  ptr_ = str;
46  if (str != NULL)
47    length_ = static_cast<int32_t>(uprv_strlen(str));
48  else
49    length_ = 0;
50}
51
52U_EXPORT UBool U_EXPORT2
53operator==(const StringPiece& x, const StringPiece& y) {
54  int32_t len = x.size();
55  if (len != y.size()) {
56    return false;
57  }
58  if (len == 0) {
59    return true;
60  }
61  const char* p = x.data();
62  const char* p2 = y.data();
63  // Test last byte in case strings share large common prefix
64  --len;
65  if (p[len] != p2[len]) return false;
66  // At this point we can, but don't have to, ignore the last byte.
67  return uprv_memcmp(p, p2, len) == 0;
68}
69
70
71/* Microsoft Visual Studio (even 2013) complains about redefinition of this
72 * static const class variable. However, the C++ standard states that this
73 * definition is correct. Perhaps there is a bug in the Microsoft compiler.
74 * This is not an issue on any other compilers (that we know of).
75 * Cygwin with MSVC 9.0 also complains here about redefinition.
76 */
77#if (!defined(_MSC_VER) || (_MSC_VER > 1800)) && !defined(CYGWINMSVC)
78const int32_t StringPiece::npos = 0x7fffffff;
79#endif
80
81U_NAMESPACE_END
82