]> git.saurik.com Git - apt.git/blame - apt-pkg/tagfile.cc
Small cosmetic fixes
[apt.git] / apt-pkg / tagfile.cc
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1// -*- mode: cpp; mode: fold -*-
2// Description /*{{{*/
0e66b144 3// $Id: tagfile.cc,v 1.16 1998/11/28 03:54:29 jgg Exp $
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4/* ######################################################################
5
6 Fast scanner for RFC-822 type header information
7
ad00ae81 8 This uses a rotating buffer to load the package information into.
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9 The scanner runs over it and isolates and indexes a single section.
10
11 ##################################################################### */
12 /*}}}*/
13// Include Files /*{{{*/
6c139d6e 14#ifdef __GNUG__
094a497d 15#pragma implementation "apt-pkg/tagfile.h"
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16#endif
17
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18#include <apt-pkg/tagfile.h>
19#include <apt-pkg/error.h>
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20
21#include <string>
22#include <stdio.h>
23 /*}}}*/
24
25// TagFile::pkgTagFile - Constructor /*{{{*/
26// ---------------------------------------------------------------------
27/* */
8e06abb2 28pkgTagFile::pkgTagFile(FileFd &Fd,unsigned long Size) : Fd(Fd), Size(Size)
578bfd0a 29{
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30 Buffer = new char[Size];
31 Start = End = Buffer;
578bfd0a 32 Left = Fd.Size();
dcb79bae 33 iOffset = 0;
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34 Fill();
35}
36 /*}}}*/
37// TagFile::Step - Advance to the next section /*{{{*/
38// ---------------------------------------------------------------------
39/* If the Section Scanner fails we refill the buffer and try again. */
40bool pkgTagFile::Step(pkgTagSection &Tag)
41{
42 if (Tag.Scan(Start,End - Start) == false)
43 {
44 if (Fill() == false)
45 return false;
46
47 if (Tag.Scan(Start,End - Start) == false)
48 return _error->Error("Unable to parse package file");
49 }
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50 Start += Tag.size();
51 iOffset += Tag.size();
52
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53 return true;
54}
55 /*}}}*/
56// TagFile::Fill - Top up the buffer /*{{{*/
57// ---------------------------------------------------------------------
58/* This takes the bit at the end of the buffer and puts it at the start
59 then fills the rest from the file */
60bool pkgTagFile::Fill()
61{
ad00ae81 62 unsigned long EndSize = End - Start;
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63
64 if (Left == 0)
65 {
ad00ae81 66 if (EndSize <= 1)
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67 return false;
68 return true;
69 }
70
ad00ae81 71 memmove(Buffer,Start,EndSize);
578bfd0a 72 Start = Buffer;
ad00ae81 73 End = Buffer + EndSize;
578bfd0a 74
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75 // See if only a bit of the file is left
76 if (Left < Size - (End - Buffer))
578bfd0a 77 {
ad00ae81 78 if (Fd.Read(End,Left) == false)
578bfd0a 79 return false;
c88edf1d 80
ad00ae81 81 End += Left;
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82 Left = 0;
83 }
84 else
85 {
ad00ae81 86 if (Fd.Read(End,Size - (End - Buffer)) == false)
578bfd0a 87 return false;
c88edf1d 88
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89 Left -= Size - (End - Buffer);
90 End = Buffer + Size;
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91 }
92 return true;
93}
94 /*}}}*/
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95// TagFile::Jump - Jump to a pre-recorded location in the file /*{{{*/
96// ---------------------------------------------------------------------
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97/* This jumps to a pre-recorded file location and reads the record
98 that is there */
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99bool pkgTagFile::Jump(pkgTagSection &Tag,unsigned long Offset)
100{
101 iOffset = Offset;
102 Left = Fd.Size() - Offset;
103 if (Fd.Seek(Offset) == false)
104 return false;
105 End = Start = Buffer;
106
107 if (Fill() == false)
108 return false;
109
110 if (Tag.Scan(Start,End - Start) == false)
111 return _error->Error("Unable to parse package file");
112 return true;
113}
114 /*}}}*/
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115// TagSection::Scan - Scan for the end of the header information /*{{{*/
116// ---------------------------------------------------------------------
117/* This looks for the first double new line in the data stream. It also
118 indexes the tags in the section. */
119bool pkgTagSection::Scan(const char *Start,unsigned long MaxLength)
120{
121 const char *End = Start + MaxLength;
122 Stop = Section = Start;
123
124 TagCount = 0;
125 Indexes[TagCount++] = Stop - Section;
126 Stop++;
127 for (; Stop < End; Stop++)
128 {
129 if (Stop[-1] != '\n')
130 continue;
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131
132 // Skip line feeds
133 for (; Stop[0] == '\r' && Stop < End; Stop++);
134
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135 if (Stop[0] == '\n')
136 {
137 // Extra one at the end to simplify find
138 Indexes[TagCount] = Stop - Section;
0a8e3465 139 for (; (Stop[0] == '\n' || Stop[0] == '\r') && Stop < End; Stop++);
578bfd0a 140 return true;
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141 }
142
143 if (isspace(Stop[0]) == 0)
144 Indexes[TagCount++] = Stop - Section;
145
146 // Just in case.
147 if (TagCount > sizeof(Indexes)/sizeof(Indexes[0]))
148 TagCount = sizeof(Indexes)/sizeof(Indexes[0]);
149 }
150 return false;
151}
152 /*}}}*/
153// TagSection::Find - Locate a tag /*{{{*/
154// ---------------------------------------------------------------------
155/* This searches the section for a tag that matches the given string. */
156bool pkgTagSection::Find(const char *Tag,const char *&Start,
157 const char *&End)
158{
159 unsigned int Length = strlen(Tag);
160 for (unsigned int I = 0; I != TagCount; I++)
161 {
162 if (strncasecmp(Tag,Section + Indexes[I],Length) != 0)
163 continue;
164
165 // Make sure the colon is in the right place
166 const char *C = Section + Length + Indexes[I];
167 for (; isspace(*C) != 0; C++);
168 if (*C != ':')
169 continue;
170
171 // Strip off the gunk from the start end
172 Start = C;
173 End = Section + Indexes[I+1];
174 for (; (isspace(*Start) != 0 || *Start == ':') && Start < End; Start++);
175 for (; isspace(End[-1]) != 0 && End > Start; End--);
0a8e3465 176
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177 return true;
178 }
179 Start = End = 0;
180 return false;
181}
182 /*}}}*/
0e66b144 183// TagSection::FindS - Find a string /*{{{*/
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184// ---------------------------------------------------------------------
185/* */
186string pkgTagSection::FindS(const char *Tag)
187{
188 const char *Start;
189 const char *End;
190 if (Find(Tag,Start,End) == false)
191 return string();
192 return string(Start,End);
193}
194 /*}}}*/
195// TagSection::FindI - Find an integer /*{{{*/
196// ---------------------------------------------------------------------
197/* */
198unsigned int pkgTagSection::FindI(const char *Tag)
199{
200 const char *Start;
201 const char *End;
202 if (Find(Tag,Start,End) == false)
203 return 0;
204
205 return atoi(string(Start,End).c_str());
206}
207 /*}}}*/
0e66b144 208