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