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Attempt to skip and resync any seriously broken semantics in package sections.
[apt-legacy.git] / apt-pkg / policy.cc
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1// -*- mode: cpp; mode: fold -*-
2// Description /*{{{*/
3// $Id: policy.cc,v 1.10 2003/08/12 00:17:37 mdz Exp $
4/* ######################################################################
5
6 Package Version Policy implementation
7
8 This is just a really simple wrapper around pkgVersionMatch with
9 some added goodies to manage the list of things..
10
11 Priority Table:
12
13 1000 -> inf = Downgradeable priorities
14 1000 = The 'no downgrade' pseduo-status file
15 100 -> 1000 = Standard priorities
16 990 = Config file override package files
17 989 = Start for preference auto-priorities
18 500 = Default package files
19 100 = The status file
20 0 -> 100 = NotAutomatic sources like experimental
21 -inf -> 0 = Never selected
22
23 ##################################################################### */
24 /*}}}*/
25// Include Files /*{{{*/
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26#include <apt-pkg/policy.h>
27#include <apt-pkg/configuration.h>
28#include <apt-pkg/tagfile.h>
29#include <apt-pkg/strutl.h>
0e5943eb 30#include <apt-pkg/fileutl.h>
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31#include <apt-pkg/error.h>
32#include <apt-pkg/sptr.h>
0e5943eb 33
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34#include <apti18n.h>
35
36#include <iostream>
00ec24d0 37#include <sstream>
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38 /*}}}*/
39
40using namespace std;
41
42// Policy::Init - Startup and bind to a cache /*{{{*/
43// ---------------------------------------------------------------------
44/* Set the defaults for operation. The default mode with no loaded policy
45 file matches the V0 policy engine. */
46pkgPolicy::pkgPolicy(pkgCache *Owner) : Pins(0), PFPriority(0), Cache(Owner)
47{
48 PFPriority = new signed short[Owner->Head().PackageFileCount];
49 Pins = new Pin[Owner->Head().PackageCount];
50
51 for (unsigned long I = 0; I != Owner->Head().PackageCount; I++)
52 Pins[I].Type = pkgVersionMatch::None;
53
54 // The config file has a master override.
55 string DefRel = _config->Find("APT::Default-Release");
56 if (DefRel.empty() == false)
57 CreatePin(pkgVersionMatch::Release,"",DefRel,990);
58
59 InitDefaults();
60}
61 /*}}}*/
62// Policy::InitDefaults - Compute the default selections /*{{{*/
63// ---------------------------------------------------------------------
64/* */
65bool pkgPolicy::InitDefaults()
66{
67 // Initialize the priorities based on the status of the package file
68 for (pkgCache::PkgFileIterator I = Cache->FileBegin(); I != Cache->FileEnd(); I++)
69 {
70 PFPriority[I->ID] = 500;
71 if ((I->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource)
72 PFPriority[I->ID] = 100;
73 else
74 if ((I->Flags & pkgCache::Flag::NotAutomatic) == pkgCache::Flag::NotAutomatic)
75 PFPriority[I->ID] = 1;
76 }
77
78 // Apply the defaults..
79 SPtrArray<bool> Fixed = new bool[Cache->HeaderP->PackageFileCount];
80 memset(Fixed,0,sizeof(*Fixed)*Cache->HeaderP->PackageFileCount);
81 signed Cur = 989;
82 StatusOverride = false;
83 for (vector<Pin>::const_iterator I = Defaults.begin(); I != Defaults.end();
84 I++, Cur--)
85 {
86 pkgVersionMatch Match(I->Data,I->Type);
87 for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); F++)
88 {
89 if (Match.FileMatch(F) == true && Fixed[F->ID] == false)
90 {
91 if (I->Priority != 0 && I->Priority > 0)
92 Cur = I->Priority;
93
94 if (I->Priority < 0)
95 PFPriority[F->ID] = I->Priority;
96 else
97 PFPriority[F->ID] = Cur;
98
99 if (PFPriority[F->ID] > 1000)
100 StatusOverride = true;
101
102 Fixed[F->ID] = true;
103 }
104 }
105 }
106
107 if (_config->FindB("Debug::pkgPolicy",false) == true)
108 for (pkgCache::PkgFileIterator F = Cache->FileBegin(); F != Cache->FileEnd(); F++)
109 cout << "Prio of " << F.FileName() << ' ' << PFPriority[F->ID] << endl;
110
111 return true;
112}
113 /*}}}*/
114// Policy::GetCandidateVer - Get the candidate install version /*{{{*/
115// ---------------------------------------------------------------------
116/* Evaluate the package pins and the default list to deteremine what the
117 best package is. */
118pkgCache::VerIterator pkgPolicy::GetCandidateVer(pkgCache::PkgIterator Pkg)
119{
120 // Look for a package pin and evaluate it.
121 signed Max = GetPriority(Pkg);
122 pkgCache::VerIterator Pref = GetMatch(Pkg);
123
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124 // no package = no candidate version
125 if (Pkg.end() == true)
126 return Pref;
127
128 // packages with a pin lower than 0 have no newer candidate than the current version
129 if (Max < 0)
130 return Pkg.CurrentVer();
131
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132 /* Falling through to the default version.. Setting Max to zero
133 effectively excludes everything <= 0 which are the non-automatic
134 priorities.. The status file is given a prio of 100 which will exclude
135 not-automatic sources, except in a single shot not-installed mode.
136 The second pseduo-status file is at prio 1000, above which will permit
137 the user to force-downgrade things.
138
139 The user pin is subject to the same priority rules as default
140 selections. Thus there are two ways to create a pin - a pin that
141 tracks the default when the default is taken away, and a permanent
142 pin that stays at that setting.
143 */
144 for (pkgCache::VerIterator Ver = Pkg.VersionList(); Ver.end() == false; Ver++)
145 {
146 for (pkgCache::VerFileIterator VF = Ver.FileList(); VF.end() == false; VF++)
147 {
148 /* If this is the status file, and the current version is not the
149 version in the status file (ie it is not installed, or somesuch)
150 then it is not a candidate for installation, ever. This weeds
151 out bogus entries that may be due to config-file states, or
152 other. */
153 if ((VF.File()->Flags & pkgCache::Flag::NotSource) == pkgCache::Flag::NotSource &&
154 Pkg.CurrentVer() != Ver)
155 continue;
156
157 signed Prio = PFPriority[VF.File()->ID];
158 if (Prio > Max)
159 {
160 Pref = Ver;
161 Max = Prio;
162 }
163 }
164
165 if (Pkg.CurrentVer() == Ver && Max < 1000)
166 {
167 /* Elevate our current selection (or the status file itself)
168 to the Pseudo-status priority. */
169 if (Pref.end() == true)
170 Pref = Ver;
171 Max = 1000;
172
173 // Fast path optimize.
174 if (StatusOverride == false)
175 break;
176 }
177 }
178 return Pref;
179}
180 /*}}}*/
181// Policy::CreatePin - Create an entry in the pin table.. /*{{{*/
182// ---------------------------------------------------------------------
183/* For performance we have 3 tables, the default table, the main cache
184 table (hashed to the cache). A blank package name indicates the pin
185 belongs to the default table. Order of insertion matters here, the
186 earlier defaults override later ones. */
187void pkgPolicy::CreatePin(pkgVersionMatch::MatchType Type,string Name,
188 string Data,signed short Priority)
189{
190 Pin *P = 0;
191
192 if (Name.empty() == true)
193 P = &*Defaults.insert(Defaults.end(),PkgPin());
194 else
195 {
196 // Get a spot to put the pin
197 pkgCache::PkgIterator Pkg = Cache->FindPkg(Name);
198 if (Pkg.end() == true)
199 {
200 // Check the unmatched table
201 for (vector<PkgPin>::iterator I = Unmatched.begin();
202 I != Unmatched.end() && P == 0; I++)
203 if (I->Pkg == Name)
204 P = &*I;
205
206 if (P == 0)
207 P = &*Unmatched.insert(Unmatched.end(),PkgPin());
208 }
209 else
210 {
211 P = Pins + Pkg->ID;
212 }
213 }
214
215 // Set..
216 P->Type = Type;
217 P->Priority = Priority;
218 P->Data = Data;
219}
220 /*}}}*/
221// Policy::GetMatch - Get the matching version for a package pin /*{{{*/
222// ---------------------------------------------------------------------
223/* */
224pkgCache::VerIterator pkgPolicy::GetMatch(pkgCache::PkgIterator Pkg)
225{
226 const Pin &PPkg = Pins[Pkg->ID];
227 if (PPkg.Type != pkgVersionMatch::None)
228 {
229 pkgVersionMatch Match(PPkg.Data,PPkg.Type);
230 return Match.Find(Pkg);
231 }
232 return pkgCache::VerIterator(*Pkg.Cache());
233}
234 /*}}}*/
235// Policy::GetPriority - Get the priority of the package pin /*{{{*/
236// ---------------------------------------------------------------------
237/* */
238signed short pkgPolicy::GetPriority(pkgCache::PkgIterator const &Pkg)
239{
240 if (Pins[Pkg->ID].Type != pkgVersionMatch::None)
241 {
242 // In this case 0 means default priority
243 if (Pins[Pkg->ID].Priority == 0)
244 return 989;
245 return Pins[Pkg->ID].Priority;
246 }
247
248 return 0;
249}
250 /*}}}*/
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251// PreferenceSection class - Overriding the default TrimRecord method /*{{{*/
252// ---------------------------------------------------------------------
253/* The preference file is a user generated file so the parser should
254 therefore be a bit more friendly by allowing comments and new lines
255 all over the place rather than forcing a special format */
256class PreferenceSection : public pkgTagSection
257{
258 void TrimRecord(bool BeforeRecord, const char* &End)
259 {
260 for (; Stop < End && (Stop[0] == '\n' || Stop[0] == '\r' || Stop[0] == '#'); Stop++)
261 if (Stop[0] == '#')
262 Stop = (const char*) memchr(Stop,'\n',End-Stop);
263 }
264};
265 /*}}}*/
266// ReadPinDir - Load the pin files from this dir into a Policy /*{{{*/
267// ---------------------------------------------------------------------
268/* This will load each pin file in the given dir into a Policy. If the
269 given dir is empty the dir set in Dir::Etc::PreferencesParts is used.
270 Note also that this method will issue a warning if the dir does not
271 exists but it will return true in this case! */
272bool ReadPinDir(pkgPolicy &Plcy,string Dir)
273{
274 if (Dir.empty() == true)
275 Dir = _config->FindDir("Dir::Etc::PreferencesParts");
276
277 if (FileExists(Dir) == false)
278 {
279 _error->WarningE("FileExists",_("Unable to read %s"),Dir.c_str());
280 return true;
281 }
282
283 vector<string> const List = GetListOfFilesInDir(Dir, "pref", true, true);
da6ee469 284
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285 // Read the files
286 for (vector<string>::const_iterator I = List.begin(); I != List.end(); I++)
287 if (ReadPinFile(Plcy, *I) == false)
288 return false;
289 return true;
290}
291 /*}}}*/
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292// ReadPinFile - Load the pin file into a Policy /*{{{*/
293// ---------------------------------------------------------------------
294/* I'd like to see the preferences file store more than just pin information
295 but right now that is the only stuff I have to store. Later there will
296 have to be some kind of combined super parser to get the data into all
297 the right classes.. */
298bool ReadPinFile(pkgPolicy &Plcy,string File)
299{
300 if (File.empty() == true)
301 File = _config->FindFile("Dir::Etc::Preferences");
302
303 if (FileExists(File) == false)
304 return true;
305
306 FileFd Fd(File,FileFd::ReadOnly);
307 pkgTagFile TF(&Fd);
308 if (_error->PendingError() == true)
309 return false;
310
0e5943eb 311 PreferenceSection Tags;
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312 while (TF.Step(Tags) == true)
313 {
314 string Name = Tags.FindS("Package");
315 if (Name.empty() == true)
0e5943eb 316 return _error->Error(_("Invalid record in the preferences file %s, no Package header"), File.c_str());
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317 if (Name == "*")
318 Name = string();
319
320 const char *Start;
321 const char *End;
322 if (Tags.Find("Pin",Start,End) == false)
323 continue;
324
325 const char *Word = Start;
326 for (; Word != End && isspace(*Word) == 0; Word++);
327
328 // Parse the type..
329 pkgVersionMatch::MatchType Type;
330 if (stringcasecmp(Start,Word,"version") == 0 && Name.empty() == false)
331 Type = pkgVersionMatch::Version;
332 else if (stringcasecmp(Start,Word,"release") == 0)
333 Type = pkgVersionMatch::Release;
334 else if (stringcasecmp(Start,Word,"origin") == 0)
335 Type = pkgVersionMatch::Origin;
336 else
337 {
338 _error->Warning(_("Did not understand pin type %s"),string(Start,Word).c_str());
339 continue;
340 }
341 for (; Word != End && isspace(*Word) != 0; Word++);
342
343 short int priority = Tags.FindI("Pin-Priority", 0);
344 if (priority == 0)
345 {
346 _error->Warning(_("No priority (or zero) specified for pin"));
347 continue;
348 }
349
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350 istringstream s(Name);
351 string pkg;
352 while(!s.eof())
353 {
354 s >> pkg;
355 Plcy.CreatePin(Type, pkg, string(Word,End),priority);
356 };
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357 }
358
359 Plcy.InitDefaults();
360 return true;
361}
362 /*}}}*/