LibreOffice Module vcl (master)  1
TextLayoutCache.hxx
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1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
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18  */
19 
20 #pragma once
21 
22 #include <sal/types.h>
23 #include <rtl/ustring.hxx>
24 #include <o3tl/hash_combine.hxx>
25 
26 #include <vcl/dllapi.h>
27 
28 #include <hb-icu.h>
29 
30 #include <vector>
31 
32 namespace vcl::text
33 {
34 struct Run
35 {
36  int32_t nStart;
37  int32_t nEnd;
38  UScriptCode nCode;
39  Run(int32_t nStart_, int32_t nEnd_, UScriptCode nCode_)
40  : nStart(nStart_)
41  , nEnd(nEnd_)
42  , nCode(nCode_)
43  {
44  }
45 };
46 
48 {
49 public:
50  std::vector<vcl::text::Run> runs;
51  TextLayoutCache(sal_Unicode const* pStr, sal_Int32 const nEnd);
52  // Creates a cached instance.
53  static std::shared_ptr<const vcl::text::TextLayoutCache> Create(OUString const&);
54 };
55 
57 {
58  size_t operator()(const OUString& str) const
59  {
60  // Strings passed to GenericSalLayout::CreateTextLayoutCache() may be very long,
61  // and computing an entire hash could almost negate the gain of hashing. Hash just first
62  // characters, that should be good enough.
63  size_t hash
64  = rtl_ustr_hashCode_WithLength(str.getStr(), std::min<size_t>(100, str.getLength()));
65  o3tl::hash_combine(hash, str.getLength());
66  return hash;
67  }
68 };
69 
71 {
72  bool operator()(const OUString& str1, const OUString& str2) const
73  {
74  // Strings passed to GenericSalLayout::CreateTextLayoutCache() may be very long,
75  // and OUString operator == compares backwards and using hard-written code, while
76  // memcmp() compares much faster.
77  if (str1.getLength() != str2.getLength())
78  return false;
79  if (str1.getStr() == str2.getStr())
80  return true;
81  return memcmp(str1.getStr(), str2.getStr(), str1.getLength() * sizeof(str1.getStr()[0]))
82  == 0;
83  }
84 };
85 }
86 
87 /* vim:set shiftwidth=4 softtabstop=4 expandtab cinoptions=b1,g0,N-s cinkeys+=0=break: */
UScriptCode nCode
std::vector< vcl::text::Run > runs
size_t operator()(const OUString &str) const
void Create(SwFormatVertOrient &rItem, SvStream &rStrm, sal_uInt16 nVersionAbusedAsSize)
#define VCL_DLLPUBLIC
Definition: dllapi.h:29
sal_uInt16 sal_Unicode
bool operator()(const OUString &str1, const OUString &str2) const
Run(int32_t nStart_, int32_t nEnd_, UScriptCode nCode_)
std::enable_if_t<(sizeof(N)==4)> hash_combine(N &nSeed, T const *pValue, size_t nCount)