OpenSystemsDevelopment / qpdf

Commit 4f4c627b77a169e1729982fa03dd75d5035f0297

Authored by Jay Berkenbilt
1 parent 7855e18a

ClosedFileInputSource: add method to keep file open 

During periods of intensive operation on a specific file, this method
can reduce the overhead of repeated open/close operations.
Inline Side-by-side
Showing 5 changed files with 41 additions and 1 deletions
ChangeLog
  View file @4f4c627
  1 +2018-08-04 Jay Berkenbilt <ejb@ql.org>
  2 +
  3 + * Add ClosedFileInputSource::stayOpen method, enabling a
  4 + ClosedFileInputSource to stay open during manually indicated
  5 + periods of high activity, thus reducing the overhead of frequent
  6 + open/close operations.
  7 +
1 8 2018-06-23 Jay Berkenbilt <ejb@ql.org>
2 9  
3 10 * 8.1.0: release
... ...
include/qpdf/ClosedFileInputSource.hh
  View file @4f4c627
... ... @@ -55,6 +55,13 @@ class ClosedFileInputSource: public InputSource
55 55 QPDF_DLL
56 56 virtual void unreadCh(char ch);
57 57  
  58 + // The file stays open between calls to stayOpen(true) and
  59 + // stayOpen(false). You can use this to surround multiple
  60 + // operations on a single ClosedFileInputSource to reduce the
  61 + // overhead of a separate open/close on each call.
  62 + QPDF_DLL
  63 + void stayOpen(bool);
  64 +
58 65 private:
59 66 ClosedFileInputSource(ClosedFileInputSource const&);
60 67 ClosedFileInputSource& operator=(ClosedFileInputSource const&);
... ... @@ -76,6 +83,7 @@ class ClosedFileInputSource: public InputSource
76 83 std::string filename;
77 84 qpdf_offset_t offset;
78 85 FileInputSource* fis;
  86 + bool stay_open;
79 87 };
80 88 PointerHolder<Members> m;
81 89 };
... ...
libqpdf/ClosedFileInputSource.cc
  View file @4f4c627
... ... @@ -4,7 +4,8 @@
4 4 ClosedFileInputSource::Members::Members(char const* filename) :
5 5 filename(filename),
6 6 offset(0),
7   - fis(0)
  7 + fis(0),
  8 + stay_open(false)
8 9 {
9 10 }
10 11  
... ... @@ -42,6 +43,10 @@ ClosedFileInputSource::after()
42 43 {
43 44 this->last_offset = this->m->fis->getLastOffset();
44 45 this->m->offset = this->m->fis->tell();
  46 + if (this->m->stay_open)
  47 + {
  48 + return;
  49 + }
45 50 delete this->m->fis;
46 51 this->m->fis = 0;
47 52 }
... ... @@ -82,6 +87,10 @@ void
82 87 ClosedFileInputSource::rewind()
83 88 {
84 89 this->m->offset = 0;
  90 + if (this->m->fis)
  91 + {
  92 + this->m->fis->rewind();
  93 + }
85 94 }
86 95  
87 96 size_t
... ... @@ -101,3 +110,13 @@ ClosedFileInputSource::unreadCh(char ch)
101 110 // Don't call after -- the file has to stay open after this
102 111 // operation.
103 112 }
  113 +
  114 +void
  115 +ClosedFileInputSource::stayOpen(bool val)
  116 +{
  117 + this->m->stay_open = val;
  118 + if ((! val) && this->m->fis)
  119 + {
  120 + after();
  121 + }
  122 +}
... ...
libtests/closed_file_input_source.cc
  View file @4f4c627
... ... @@ -65,6 +65,11 @@ int main()
65 65 std::cout << "testing with ClosedFileInputSource\n";
66 66 ClosedFileInputSource cf("input");
67 67 do_tests(&cf);
  68 + std::cout << "testing with ClosedFileInputSource in stay open mode\n";
  69 + ClosedFileInputSource cf2("input");
  70 + cf2.stayOpen(true);
  71 + do_tests(&cf2);
  72 + cf2.stayOpen(false);
68 73 std::cout << "testing with FileInputSource\n";
69 74 FileInputSource f;
70 75 f.setFilename("input");
... ...
libtests/qtest/closedfile/output
  View file @4f4c627
1 1 testing with ClosedFileInputSource
  2 +testing with ClosedFileInputSource in stay open mode
2 3 testing with FileInputSource
3 4 all assertions passed
... ...