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 namespace EDSP                                                          /*{{{*/
  31 {
  32         /** \brief creates the EDSP request stanza
  33          *
  34          *  In the EDSP protocol the first thing send to the resolver is a stanza
  35          *  encoding the request. This method will write this stanza by looking at
  36          *  the given Cache and requests the installation of all packages which were
  37          *  marked for installation in it (equally for remove).
  38          *
  39          *  \param Cache in which the request is encoded
  40          *  \param output is written to this "file"
  41          *  \param upgrade is true if it is an request like apt-get upgrade
  42          *  \param distUpgrade is true if it is a request like apt-get dist-upgrade
  43          *  \param autoRemove is true if removal of unneeded packages should be performed
  44          *  \param Progress is an instance to report progress to
  45          *
  46          *  \return true if request was composed successfully, otherwise false
  47          */
  48         bool WriteRequest(pkgDepCache &Cache, FILE* output,
  49                                  bool const upgrade = false,
  50                                  bool const distUpgrade = false,
  51                                  bool const autoRemove = false,
  52                                 OpProgress *Progress = NULL);
  53
  54         /** \brief creates the scenario representing the package universe
  55          *
  56          *  After the request all known information about a package are send
  57          *  to the solver. The output looks similar to a Packages or status file
  58          *
  59          *  All packages and version included in this Cache are send, even if
  60          *  it doesn't make sense from an APT resolver point of view like versions
  61          *  with a negative pin to enable the solver to propose even that as a
  62          *  solution or at least to be able to give a hint what can be done to
  63          *  statisfy a request.
  64          *
  65          *  \param Cache is the known package universe
  66          *  \param output is written to this "file"
  67          *  \param Progress is an instance to report progress to
  68          *
  69          *  \return true if universe was composed successfully, otherwise false
  70          */
  71         bool WriteScenario(pkgDepCache &Cache, FILE* output, OpProgress *Progress = NULL);
  72
  73         /** \brief creates a limited scenario representing the package universe
  74          *
  75          *  This method works similar to #WriteScenario as it works in the same
  76          *  way but doesn't send the complete universe to the solver but only
  77          *  packages included in the pkgset which will have only dependencies
  78          *  on packages which are in the given set. All other dependencies will
  79          *  be removed, so that this method can be used to create testcases
  80          *
  81          *  \param Cache is the known package universe
  82          *  \param output is written to this "file"
  83          *  \param pkgset is a set of packages the universe should be limited to
  84          *  \param Progress is an instance to report progress to
  85          *
  86          *  \return true if universe was composed successfully, otherwise false
  87          */
  88         bool WriteLimitedScenario(pkgDepCache &Cache, FILE* output,
  89                                          APT::PackageSet const &pkgset,
  90                                          OpProgress *Progress = NULL);
  91
  92         /** \brief waits and acts on the information returned from the solver
  93          *
  94          *  This method takes care of interpreting whatever the solver sends
  95          *  through the standard output like a solution, progress or an error.
  96          *  The main thread should handle his control over to this method to
  97          *  wait for the solver to finish the given task
  98          *
  99          *  \param input file descriptor with the response from the solver
 100          *  \param Cache the solution should be applied on if any
 101          *  \param Progress is an instance to report progress to
 102          *
 103          *  \return true if a solution is found and applied correctly, otherwise false
 104          */
 105         bool ReadResponse(int const input, pkgDepCache &Cache, OpProgress *Progress = NULL);
 106
 107         /** \brief search and read the request stanza for action later
 108          *
 109          *  This method while ignore the input up to the point it finds the
 110          *  Request: line as an indicator for the Request stanza.
 111          *  The request is stored in the parameters install and remove then,
 112          *  as the cache isn't build yet as the scenario follows the request.
 113          *
 114          *  \param input file descriptor with the edsp input for the solver
 115          *  \param[out] install is a list which gets populated with requested installs
 116          *  \param[out] remove is a list which gets populated with requested removals
 117          *  \param[out] upgrade is true if it is a request like apt-get upgrade
 118          *  \param[out] distUpgrade is true if it is a request like apt-get dist-upgrade
 119          *  \param[out] autoRemove is true if removal of uneeded packages should be performed
 120          *
 121          *  \return true if the request could be found and worked on, otherwise false
 122          */
 123         bool ReadRequest(int const input, std::list<std::string> &install,
 124                         std::list<std::string> &remove, bool &upgrade,
 125                         bool &distUpgrade, bool &autoRemove);
 126
 127         /** \brief takes the request lists and applies it on the cache
 128          *
 129          *  The lists as created by #ReadRequest will be used to find the
 130          *  packages in question and mark them for install/remove.
 131          *  No solving is done and no auto-install/-remove.
 132          *
 133          *  \param install is a list of packages to mark for installation
 134          *  \param remove is a list of packages to mark for removal
 135          *  \param Cache is there the markers should be set
 136          *
 137          *  \return false if the request couldn't be applied, true otherwise
 138          */
 139         bool ApplyRequest(std::list<std::string> const &install,
 140                                  std::list<std::string> const &remove,
 141                                  pkgDepCache &Cache);
 142
 143         /** \brief encodes the changes in the Cache as a EDSP solution
 144          *
 145          *  The markers in the Cache are observed and send to given
 146          *  file. The solution isn't checked for consistency or alike,
 147          *  so even broken solutions can be written successfully,
 148          *  but the front-end revicing it will properly fail then.
 149          *
 150          *  \param Cache which represents the solution
 151          *  \param output to write the stanzas forming the solution to
 152          *
 153          *  \return true if solution could be written, otherwise false
 154          */
 155         bool WriteSolution(pkgDepCache &Cache, FILE* output);
 156
 157         /** \brief sends a progress report
 158          *
 159          *  \param percent of the solving completed
 160          *  \param message the solver wants the user to see
 161          *  \param output the front-end listens for progress report
 162          */
 163         bool WriteProgress(unsigned short const percent, const char* const message, FILE* output);
 164
 165         /** \brief sends an error report
 166          *
 167          *  Solvers are expected to execute successfully even if
 168          *  they were unable to calculate a solution for a given task.
 169          *  Obviously they can't send a solution through, so this
 170          *  methods deals with formatting an error message correctly
 171          *  so that the front-ends can receive and display it.
 172          *
 173          *  The first line of the message should be a short description
 174          *  of the error so it can be used for dialog titles or alike
 175          *
 176          *  \param uuid of this error message
 177          *  \param message is free form text to describe the error
 178          *  \param output the front-end listens for error messages
 179          */
 180         bool WriteError(char const * const uuid, std::string const &message, FILE* output);
 181
 182
 183         /** \brief executes the given solver and returns the pipe ends
 184          *
 185          *  The given solver is executed if it can be found in one of the
 186          *  configured directories and setup for it is performed.
 187          *
 188          *  \param solver to execute
 189          *  \param[out] solver_in will be the stdin of the solver
 190          *  \param[out] solver_out will be the stdout of the solver
 191          *
 192          *  \return PID of the started solver or 0 if failure occurred
 193          */
 194         pid_t ExecuteSolver(const char* const solver, int * const solver_in, int * const solver_out, bool /*overload*/);
 195         APT_DEPRECATED_MSG("add a dummy bool parameter to use the overload returning a pid_t") bool ExecuteSolver(const char* const solver, int *solver_in, int *solver_out);
 196
 197         /** \brief call an external resolver to handle the request
 198          *
 199          *  This method wraps all the methods above to call an external solver
 200          *
 201          *  \param solver to execute
 202          *  \param Cache with the problem and as universe to work in
 203          *  \param upgrade is true if it is a request like apt-get upgrade
 204          *  \param distUpgrade is true if it is a request like apt-get dist-upgrade
 205          *  \param autoRemove is true if unneeded packages should be removed
 206          *  \param Progress is an instance to report progress to
 207          *
 208          *  \return true if the solver has successfully solved the problem,
 209          *  otherwise false
 210          */
 211         bool ResolveExternal(const char* const solver, pkgDepCache &Cache,
 212                                     bool const upgrade, bool const distUpgrade,
 213                                     bool const autoRemove, OpProgress *Progress = NULL);
 214 }
 215                                                                         /*}}}*/
 216 #endif