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httptextlog.C
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1/// \file
2/// \ingroup tutorial_http
3/// This macro demonstrates custom access and custom drawing for TMsgList class
4/// Main motivation for this example - demonstrate how traffic between server and
5/// client can be minimized and how one could build custom UI in the browser
6///
7/// TMsgList in this tutorial keep last N messages, numbering each with unique identifier
8/// There is TMsgList::Select() method which selects messages from the list
9/// If one specifies identifier, only messages newer than this identifier are selected
10/// In the selection list (TList object of TObjString) first item always identifier for
11/// the latest message in the list
12///
13/// In JavaScript code (httptextlog.js) one uses Select() method to receive latest
14/// messages, which not yet been seen in the browser and display them as text
15/// At maximum, 1000 elements are preserved in the browser.
16///
17/// After macro started, one could open in browser address
18/// ~~~
19/// http://localhost:8080?item=log
20/// ~~~
21/// One could either click item again or enable monitoring to always receive latest messages
22/// Or one could open only this output and nothing else:
23/// ~~~
24/// http://localhost:8080/log/draw.htm?monitoring=2000
25/// ~~~
26/// In last case it could be used in iframe, also it requires less code to load on the page
27///
28/// \macro_code
29///
30/// \author Sergey Linev
31
32
33#include <stdio.h>
34#include <string.h>
35
36#include "TNamed.h"
37#include "TList.h"
38#include "TObjString.h"
39#include "TH1.h"
40#include "TH2.h"
41#include "TRandom3.h"
42#include "TSystem.h"
43#include "THttpServer.h"
44#include "TRootSniffer.h"
45#include "TDatime.h"
46#include "TClass.h"
47
48Bool_t bRun = kTRUE;
49
50class TMsgList : public TNamed {
51
52 protected:
53
54 TList fMsgs; // list messages, stored as TObjString
55 Int_t fLimit; // max number of stored messages
56 Long64_t fCounter; // current message id
57 TList fSelect; //! temporary list used for selection
58 TObjString fStrCounter; //! current id stored in the string
59
60 public:
61
62 TMsgList(const char* name = "log", Int_t limit = 1000) :
63 TNamed(name,"list of log messages"),
64 fMsgs(),
65 fLimit(limit),
66 fCounter(0),
67 fSelect(),
68 fStrCounter()
69 {
70 fMsgs.SetOwner(kTRUE);
71
72 // counter initialized from current time
73 // if application restarted, id will be bigger and request from browser
74 // will not lead to messages lost. Of course, if more than 1000 messages
75 // per second are generated, one could have mismatch
76
77 fCounter = ((Long64_t) TDatime().Get()) * 1000;
78 }
79
80 virtual ~TMsgList() { fMsgs.Clear(); }
81
82 void AddMsg(const char* msg)
83 {
84 // add message to the list
85 // if number of stored messages bigger than configured, old messages will be removed
86 // zero (msg==0) messages will not be add to the list
87
88 while (fMsgs.GetSize() >= fLimit) {
89 TObject* last = fMsgs.Last();
90 fMsgs.RemoveLast();
91 delete last;
92 }
93 if (msg==0) return;
94
95 fMsgs.AddFirst(new TObjString(msg));
96 fCounter++;
97 }
98
99 TList* Select(Int_t max = 0, Long64_t id = 0)
100 {
101 // Central method to select new messages
102 // Current id stored as first item and used on the client to request new portion
103 // One could limit number of returned messages
104
105 TIter iter(&fMsgs);
106 TObject* obj = 0;
107 Long64_t curr = fCounter;
108 fSelect.Clear();
109
110 if (max == 0) max = fMsgs.GetLast()+1;
111
112 // add current id as first string in the list
113 fStrCounter.SetString(TString::LLtoa(fCounter, 10));
114 fSelect.Add(&fStrCounter);
115
116 while (((obj = iter()) != 0) && (--curr >= id) && (--max>=0)) fSelect.Add(obj);
117
118 return &fSelect;
119 }
120
121 ClassDef(TMsgList, 1); // Custom messages list
122};
123
124void httptextlog()
125{
126 // create logging instance
127 TMsgList* log = new TMsgList("log", 200);
128
129 if ((TMsgList::Class()->GetMethodAllAny("Select") == 0) || (strcmp(log->ClassName(), "TMsgList")!=0)) {
130 printf("Most probably, macro runs in interpreter mode\n");
131 printf("To access new methods from TMsgList class,\n");
132 printf("one should run macro with ACLiC like:\n");
133 printf(" shell> root -b httpextlog.C+\n");
134 return;
135 }
136
137 if (gSystem->AccessPathName("httptextlog.js")!=0) {
138 printf("Please start macro from directory where httptextlog.js is available\n");
139 printf("Only in this case web interface can work\n");
140 return;
141 }
142
143 // create histograms, just for fun
144 TH1D *hpx = new TH1D("hpx","This is the px distribution",100,-4,4);
145 hpx->SetFillColor(48);
146 hpx->SetDirectory(0);
147 TH2F *hpxpy = new TH2F("hpxpy","py vs px",40,-4,4,40,-4,4);
148 hpxpy->SetDirectory(0);
149
150 // start http server
151 THttpServer* serv = new THttpServer("http:8080");
152
153 // One could specify location of newer version of JSROOT
154 // serv->SetJSROOT("https://root.cern.ch/js/latest/");
155 // serv->SetJSROOT("http://jsroot.gsi.de/latest/");
156
157 // let always load httptextlog.js script in the browser
158 serv->GetSniffer()->SetAutoLoad("currentdir/httptextlog.js");
159
160 // register histograms
161 serv->Register("/", hpx);
162 serv->Register("/", hpxpy);
163
164 // register log instance
165 serv->Register("/", log);
166
167 // while server runs in read-only mode, we should allow methods execution
168 serv->Restrict("/log", "allow_method=Select,GetTitle");
169
170 // register exit command
171 serv->RegisterCommand("/Stop","bRun=kFALSE;", "rootsys/icons/ed_delete.png");
172 serv->RegisterCommand("/ExitRoot","gSystem->Exit(1);", "rootsys/icons/ed_delete.png");
173
174 // Fill histograms randomly
175 TRandom3 random;
176 Float_t px, py;
177 const Long_t kUPDATE = 1000;
178 Long_t cnt = 0;
179 while (bRun) {
180 random.Rannor(px,py);
181 hpx->Fill(px);
182 hpxpy->Fill(px,py);
183
184 // IMPORTANT: one should regularly call ProcessEvents
185 if (cnt++ % kUPDATE == 0) {
186 if (gSystem->ProcessEvents()) break;
187
188 Long_t loop = cnt / kUPDATE;
189
190 // make messages not very often
191 if (loop % 1000 == 0) {
192 loop = loop/1000;
193 int shift = loop % 40;
194 // make a 'stairs' with spaces
195 log->AddMsg(TString::Format("%*s Message %ld", shift, "", loop));
196 }
197 }
198 }
199
200 delete serv; // delete http server
201}
int Int_t
Definition RtypesCore.h:45
long Long_t
Definition RtypesCore.h:54
bool Bool_t
Definition RtypesCore.h:63
long long Long64_t
Definition RtypesCore.h:80
float Float_t
Definition RtypesCore.h:57
const Bool_t kTRUE
Definition RtypesCore.h:100
#define ClassDef(name, id)
Definition Rtypes.h:325
char name[80]
Definition TGX11.cxx:110
R__EXTERN TSystem * gSystem
Definition TSystem.h:559
virtual void SetFillColor(Color_t fcolor)
Set the fill area color.
Definition TAttFill.h:37
virtual void SetOwner(Bool_t enable=kTRUE)
Set whether this collection is the owner (enable==true) of its content.
virtual Int_t GetSize() const
Return the capacity of the collection, i.e.
This class stores the date and time with a precision of one second in an unsigned 32 bit word (950130...
Definition TDatime.h:37
UInt_t Get() const
Return raw date/time as encoded by TDatime.
Definition TDatime.cxx:240
1-D histogram with a double per channel (see TH1 documentation)}
Definition TH1.h:618
virtual void SetDirectory(TDirectory *dir)
By default, when a histogram is created, it is added to the list of histogram objects in the current ...
Definition TH1.cxx:8767
virtual Int_t Fill(Double_t x)
Increment bin with abscissa X by 1.
Definition TH1.cxx:3351
2-D histogram with a float per channel (see TH1 documentation)}
Definition TH2.h:251
Int_t Fill(Double_t)
Invalid Fill method.
Definition TH2.cxx:358
Bool_t RegisterCommand(const char *cmdname, const char *method, const char *icon=nullptr)
Register command which can be executed from web interface.
Bool_t Register(const char *subfolder, TObject *obj)
Register object in subfolder.
TRootSniffer * GetSniffer() const
returns pointer on objects sniffer
Definition THttpServer.h:87
void Restrict(const char *path, const char *options)
Restrict access to specified object.
A doubly linked list.
Definition TList.h:38
virtual void Add(TObject *obj)
Definition TList.h:81
virtual void AddFirst(TObject *obj)
Add object at the beginning of the list.
Definition TList.cxx:100
virtual void RemoveLast()
Remove the last object of the list.
Definition TList.cxx:909
virtual TObject * Last() const
Return the last object in the list. Returns 0 when list is empty.
Definition TList.cxx:693
virtual void Clear(Option_t *option="")
Remove all objects from the list.
Definition TList.cxx:402
The TNamed class is the base class for all named ROOT classes.
Definition TNamed.h:29
Collectable string class.
Definition TObjString.h:28
void SetString(const char *s)
Definition TObjString.h:45
Mother of all ROOT objects.
Definition TObject.h:41
Random number generator class based on M.
Definition TRandom3.h:27
virtual void Rannor(Float_t &a, Float_t &b)
Return 2 numbers distributed following a gaussian with mean=0 and sigma=1.
Definition TRandom.cxx:500
void SetAutoLoad(const char *scripts="")
When specified, _autoload attribute will be always add to top element of h.json/h....
virtual Int_t GetLast() const
Returns index of last object in collection.
static TString LLtoa(Long64_t value, Int_t base)
Converts a Long64_t to a TString with respect to the base specified (2-36).
Definition TString.cxx:2102
static TString Format(const char *fmt,...)
Static method which formats a string using a printf style format descriptor and return a TString.
Definition TString.cxx:2336
virtual Bool_t AccessPathName(const char *path, EAccessMode mode=kFileExists)
Returns FALSE if one can access a file using the specified access mode.
Definition TSystem.cxx:1296
virtual Bool_t ProcessEvents()
Process pending events (GUI, timers, sockets).
Definition TSystem.cxx:419
const char * cnt
Definition TXMLSetup.cxx:75