methods/server.h

   1 // -*- mode: cpp; mode: fold -*-
   2 // Description                                                          /*{{{*/
   3 /* ######################################################################
   4
   5    Classes dealing with the abstraction of talking to a end via a text
   6    protocol like HTTP (which is used by the http and https methods)
   7
   8    ##################################################################### */
   9                                                                         /*}}}*/
  10
  11 #ifndef APT_SERVER_H
  12 #define APT_SERVER_H
  13
  14 #include <apt-pkg/strutl.h>
  15 #include <apt-pkg/acquire-method.h>
  16
  17 #include <time.h>
  18 #include <iostream>
  19 #include <string>
  20 #include <memory>
  21
  22 using std::cout;
  23 using std::endl;
  24
  25 class Hashes;
  26 class ServerMethod;
  27 class FileFd;
  28
  29 struct ServerState
  30 {
  31    // This is the last parsed Header Line
  32    unsigned int Major;
  33    unsigned int Minor;
  34    unsigned int Result;
  35    char Code[360];
  36
  37    // These are some statistics from the last parsed header lines
  38
  39    // total size of the usable content (aka: the file)
  40    unsigned long long TotalFileSize;
  41    // size we actually download (can be smaller than Size if we have partial content)
  42    unsigned long long DownloadSize;
  43    // size of junk content (aka: server error pages)
  44    unsigned long long JunkSize;
  45    // The start of the data (for partial content)
  46    unsigned long long StartPos;
  47
  48    time_t Date;
  49    bool HaveContent;
  50    enum {Chunked,Stream,Closes} Encoding;
  51    enum {Header, Data} State;
  52    bool Persistent;
  53    std::string Location;
  54
  55    // This is a Persistent attribute of the server itself.
  56    bool Pipeline;
  57    URI ServerName;
  58    URI Proxy;
  59    unsigned long TimeOut;
  60
  61    unsigned long long MaximumSize;
  62
  63    protected:
  64    ServerMethod *Owner;
  65
  66    virtual bool ReadHeaderLines(std::string &Data) = 0;
  67    virtual bool LoadNextResponse(bool const ToFile, FileFd * const File) = 0;
  68
  69    public:
  70    bool HeaderLine(std::string Line);
  71
  72    /** \brief Result of the header acquire */
  73    enum RunHeadersResult {
  74       /** \brief Header ok */
  75       RUN_HEADERS_OK,
  76       /** \brief IO error while retrieving */
  77       RUN_HEADERS_IO_ERROR,
  78       /** \brief Parse error after retrieving */
  79       RUN_HEADERS_PARSE_ERROR
  80    };
  81    /** \brief Get the headers before the data */
  82    RunHeadersResult RunHeaders(FileFd * const File, const std::string &Uri);
  83    bool AddPartialFileToHashes(FileFd &File);
  84
  85    bool Comp(URI Other) const {return Other.Host == ServerName.Host && Other.Port == ServerName.Port;};
  86    virtual void Reset() {Major = 0; Minor = 0; Result = 0; Code[0] = '\0'; TotalFileSize = 0; JunkSize = 0;
  87                  StartPos = 0; Encoding = Closes; time(&Date); HaveContent = false;
  88                  State = Header; Persistent = false; Pipeline = true; MaximumSize = 0;};
  89    virtual bool WriteResponse(std::string const &Data) = 0;
  90
  91    /** \brief Transfer the data from the socket */
  92    virtual bool RunData(FileFd * const File) = 0;
  93
  94    virtual bool Open() = 0;
  95    virtual bool IsOpen() = 0;
  96    virtual bool Close() = 0;
  97    virtual bool InitHashes(HashStringList const &ExpectedHashes) = 0;
  98    virtual Hashes * GetHashes() = 0;
  99    virtual bool Die(FileFd &File) = 0;
 100    virtual bool Flush(FileFd * const File) = 0;
 101    virtual bool Go(bool ToFile, FileFd * const File) = 0;
 102
 103    ServerState(URI Srv, ServerMethod *Owner);
 104    virtual ~ServerState() {};
 105 };
 106
 107 class ServerMethod : public pkgAcqMethod
 108 {
 109    protected:
 110    virtual bool Fetch(FetchItem *) APT_OVERRIDE;
 111
 112    std::unique_ptr<ServerState> Server;
 113    std::string NextURI;
 114    FileFd *File;
 115
 116    unsigned long PipelineDepth;
 117    bool AllowRedirect;
 118
 119    // Find the biggest item in the fetch queue for the checking of the maximum
 120    // size
 121    unsigned long long FindMaximumObjectSizeInQueue() const APT_PURE;
 122
 123    public:
 124    bool Debug;
 125
 126    /** \brief Result of the header parsing */
 127    enum DealWithHeadersResult {
 128       /** \brief The file is open and ready */
 129       FILE_IS_OPEN,
 130       /** \brief We got a IMS hit, the file has not changed */
 131       IMS_HIT,
 132       /** \brief The server reported a unrecoverable error */
 133       ERROR_UNRECOVERABLE,
 134       /** \brief The server reported a error with a error content page */
 135       ERROR_WITH_CONTENT_PAGE,
 136       /** \brief An error on the client side */
 137       ERROR_NOT_FROM_SERVER,
 138       /** \brief A redirect or retry request */
 139       TRY_AGAIN_OR_REDIRECT
 140    };
 141    /** \brief Handle the retrieved header data */
 142    DealWithHeadersResult DealWithHeaders(FetchResult &Res);
 143
 144    // In the event of a fatal signal this file will be closed and timestamped.
 145    static std::string FailFile;
 146    static int FailFd;
 147    static time_t FailTime;
 148    static APT_NORETURN void SigTerm(int);
 149
 150    virtual bool Configuration(std::string Message) APT_OVERRIDE;
 151    virtual bool Flush() { return Server->Flush(File); };
 152
 153    int Loop();
 154
 155    virtual void SendReq(FetchItem *Itm) = 0;
 156    virtual std::unique_ptr<ServerState> CreateServerState(URI const &uri) = 0;
 157    virtual void RotateDNS() = 0;
 158
 159    ServerMethod(const char *Ver,unsigned long Flags = 0);
 160    virtual ~ServerMethod() {};
 161 };
 162
 163 #endif