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