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