apt-pkg/edsp.h

   1 // -*- mode: cpp; mode: fold -*-
   2 /** Description \file edsp.h                                            {{{
   3    ######################################################################
   4    Set of methods to help writing and reading everything needed for EDSP
   5    with the notable exception of reading a scenario for conversion into
   6    a Cache as this is handled by edsp interface for listparser and friends
   7    ##################################################################### */
   8                                                                         /*}}}*/
   9 #ifndef PKGLIB_EDSP_H
  10 #define PKGLIB_EDSP_H
  11
  12 #include <apt-pkg/cacheset.h>
  13 #include <apt-pkg/pkgcache.h>
  14 #include <apt-pkg/cacheiterators.h>
  15 #include <apt-pkg/macros.h>
  16
  17 #include <stdio.h>
  18
  19 #include <list>
  20 #include <string>
  21
  22 #ifndef APT_8_CLEANER_HEADERS
  23 #include <apt-pkg/depcache.h>
  24 #include <apt-pkg/progress.h>
  25 #endif
  26
  27 class pkgDepCache;
  28 class OpProgress;
  29
  30 class EDSP                                                              /*{{{*/
  31 {
  32         // we could use pkgCache::DepType and ::Priority, but these would be localized strings…
  33         static const char * const PrioMap[];
  34         static const char * const DepMap[];
  35
  36         APT_HIDDEN bool static ReadLine(int const input, std::string &line);
  37         APT_HIDDEN bool static StringToBool(char const *answer, bool const defValue);
  38
  39         APT_HIDDEN void static WriteScenarioVersion(pkgDepCache &Cache, FILE* output,
  40                                          pkgCache::PkgIterator const &Pkg,
  41                                          pkgCache::VerIterator const &Ver);
  42         APT_HIDDEN void static WriteScenarioDependency(FILE* output,
  43                                             pkgCache::VerIterator const &Ver);
  44         APT_HIDDEN void static WriteScenarioLimitedDependency(FILE* output,
  45                                                    pkgCache::VerIterator const &Ver,
  46                                                    APT::PackageSet const &pkgset);
  47 public:
  48         /** \brief creates the EDSP request stanza
  49          *
  50          *  In the EDSP protocol the first thing send to the resolver is a stanza
  51          *  encoding the request. This method will write this stanza by looking at
  52          *  the given Cache and requests the installation of all packages which were
  53          *  marked for installation in it (equally for remove).
  54          *
  55          *  \param Cache in which the request is encoded
  56          *  \param output is written to this "file"
  57          *  \param upgrade is true if it is an request like apt-get upgrade
  58          *  \param distUpgrade is true if it is a request like apt-get dist-upgrade
  59          *  \param autoRemove is true if removal of unneeded packages should be performed
  60          *  \param Progress is an instance to report progress to
  61          *
  62          *  \return true if request was composed successfully, otherwise false
  63          */
  64         bool static WriteRequest(pkgDepCache &Cache, FILE* output,
  65                                  bool const upgrade = false,
  66                                  bool const distUpgrade = false,
  67                                  bool const autoRemove = false,
  68                                 OpProgress *Progress = NULL);
  69
  70         /** \brief creates the scenario representing the package universe
  71          *
  72          *  After the request all known information about a package are send
  73          *  to the solver. The output looks similar to a Packages or status file
  74          *
  75          *  All packages and version included in this Cache are send, even if
  76          *  it doesn't make sense from an APT resolver point of view like versions
  77          *  with a negative pin to enable the solver to propose even that as a
  78          *  solution or at least to be able to give a hint what can be done to
  79          *  statisfy a request.
  80          *
  81          *  \param Cache is the known package universe
  82          *  \param output is written to this "file"
  83          *  \param Progress is an instance to report progress to
  84          *
  85          *  \return true if universe was composed successfully, otherwise false
  86          */
  87         bool static WriteScenario(pkgDepCache &Cache, FILE* output, OpProgress *Progress = NULL);
  88
  89         /** \brief creates a limited scenario representing the package universe
  90          *
  91          *  This method works similar to #WriteScenario as it works in the same
  92          *  way but doesn't send the complete universe to the solver but only
  93          *  packages included in the pkgset which will have only dependencies
  94          *  on packages which are in the given set. All other dependencies will
  95          *  be removed, so that this method can be used to create testcases
  96          *
  97          *  \param Cache is the known package universe
  98          *  \param output is written to this "file"
  99          *  \param pkgset is a set of packages the universe should be limited to
 100          *  \param Progress is an instance to report progress to
 101          *
 102          *  \return true if universe was composed successfully, otherwise false
 103          */
 104         bool static WriteLimitedScenario(pkgDepCache &Cache, FILE* output,
 105                                          APT::PackageSet const &pkgset,
 106                                          OpProgress *Progress = NULL);
 107
 108         /** \brief waits and acts on the information returned from the solver
 109          *
 110          *  This method takes care of interpreting whatever the solver sends
 111          *  through the standard output like a solution, progress or an error.
 112          *  The main thread should handle his control over to this method to
 113          *  wait for the solver to finish the given task
 114          *
 115          *  \param input file descriptor with the response from the solver
 116          *  \param Cache the solution should be applied on if any
 117          *  \param Progress is an instance to report progress to
 118          *
 119          *  \return true if a solution is found and applied correctly, otherwise false
 120          */
 121         bool static ReadResponse(int const input, pkgDepCache &Cache, OpProgress *Progress = NULL);
 122
 123         /** \brief search and read the request stanza for action later
 124          *
 125          *  This method while ignore the input up to the point it finds the
 126          *  Request: line as an indicator for the Request stanza.
 127          *  The request is stored in the parameters install and remove then,
 128          *  as the cache isn't build yet as the scenario follows the request.
 129          *
 130          *  \param input file descriptor with the edsp input for the solver
 131          *  \param[out] install is a list which gets populated with requested installs
 132          *  \param[out] remove is a list which gets populated with requested removals
 133          *  \param[out] upgrade is true if it is a request like apt-get upgrade
 134          *  \param[out] distUpgrade is true if it is a request like apt-get dist-upgrade
 135          *  \param[out] autoRemove is true if removal of uneeded packages should be performed
 136          *
 137          *  \return true if the request could be found and worked on, otherwise false
 138          */
 139         bool static ReadRequest(int const input, std::list<std::string> &install,
 140                         std::list<std::string> &remove, bool &upgrade,
 141                         bool &distUpgrade, bool &autoRemove);
 142
 143         /** \brief takes the request lists and applies it on the cache
 144          *
 145          *  The lists as created by #ReadRequest will be used to find the
 146          *  packages in question and mark them for install/remove.
 147          *  No solving is done and no auto-install/-remove.
 148          *
 149          *  \param install is a list of packages to mark for installation
 150          *  \param remove is a list of packages to mark for removal
 151          *  \param Cache is there the markers should be set
 152          *
 153          *  \return false if the request couldn't be applied, true otherwise
 154          */
 155         bool static ApplyRequest(std::list<std::string> const &install,
 156                                  std::list<std::string> const &remove,
 157                                  pkgDepCache &Cache);
 158
 159         /** \brief encodes the changes in the Cache as a EDSP solution
 160          *
 161          *  The markers in the Cache are observed and send to given
 162          *  file. The solution isn't checked for consistency or alike,
 163          *  so even broken solutions can be written successfully,
 164          *  but the front-end revicing it will properly fail then.
 165          *
 166          *  \param Cache which represents the solution
 167          *  \param output to write the stanzas forming the solution to
 168          *
 169          *  \return true if solution could be written, otherwise false
 170          */
 171         bool static WriteSolution(pkgDepCache &Cache, FILE* output);
 172
 173         /** \brief sends a progress report
 174          *
 175          *  \param percent of the solving completed
 176          *  \param message the solver wants the user to see
 177          *  \param output the front-end listens for progress report
 178          */
 179         bool static WriteProgress(unsigned short const percent, const char* const message, FILE* output);
 180
 181         /** \brief sends an error report
 182          *
 183          *  Solvers are expected to execute successfully even if
 184          *  they were unable to calculate a solution for a given task.
 185          *  Obviously they can't send a solution through, so this
 186          *  methods deals with formatting an error message correctly
 187          *  so that the front-ends can receive and display it.
 188          *
 189          *  The first line of the message should be a short description
 190          *  of the error so it can be used for dialog titles or alike
 191          *
 192          *  \param uuid of this error message
 193          *  \param message is free form text to describe the error
 194          *  \param output the front-end listens for error messages
 195          */
 196         bool static WriteError(char const * const uuid, std::string const &message, FILE* output);
 197
 198
 199         /** \brief executes the given solver and returns the pipe ends
 200          *
 201          *  The given solver is executed if it can be found in one of the
 202          *  configured directories and setup for it is performed.
 203          *
 204          *  \param solver to execute
 205          *  \param[out] solver_in will be the stdin of the solver
 206          *  \param[out] solver_out will be the stdout of the solver
 207          *
 208          *  \return true if the solver could be started and the pipes
 209          *  are set up correctly, otherwise false and the pipes are invalid
 210          */
 211         bool static ExecuteSolver(const char* const solver, int *solver_in, int *solver_out);
 212
 213         /** \brief call an external resolver to handle the request
 214          *
 215          *  This method wraps all the methods above to call an external solver
 216          *
 217          *  \param solver to execute
 218          *  \param Cache with the problem and as universe to work in
 219          *  \param upgrade is true if it is a request like apt-get upgrade
 220          *  \param distUpgrade is true if it is a request like apt-get dist-upgrade
 221          *  \param autoRemove is true if unneeded packages should be removed
 222          *  \param Progress is an instance to report progress to
 223          *
 224          *  \return true if the solver has successfully solved the problem,
 225          *  otherwise false
 226          */
 227         bool static ResolveExternal(const char* const solver, pkgDepCache &Cache,
 228                                     bool const upgrade, bool const distUpgrade,
 229                                     bool const autoRemove, OpProgress *Progress = NULL);
 230 };
 231                                                                         /*}}}*/
 232 #endif