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