rdf/base/rdfutil.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
   2 /* This Source Code Form is subject to the terms of the Mozilla Public
   3  * License, v. 2.0. If a copy of the MPL was not distributed with this
   4  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   5
   6 /*
   7
   8   Implementations for a bunch of useful RDF utility routines.  Many of
   9   these will eventually be exported outside of RDF.DLL via the
  10   nsIRDFService interface.
  11
  12   TO DO
  13
  14   1) Make this so that it doesn't permanently leak the RDF service
  15      object.
  16
  17   2) Make container functions thread-safe. They currently don't ensure
  18      that the RDF:nextVal property is maintained safely.
  19
  20  */
  21
  22 #include "nsCOMPtr.h"
  23 #include "nsIRDFDataSource.h"
  24 #include "nsIRDFNode.h"
  25 #include "nsIRDFService.h"
  26 #include "nsIServiceManager.h"
  27 #include "nsIURL.h"
  28 #include "nsIIOService.h"
  29 #include "nsIURL.h"
  30 #include "nsNetUtil.h"
  31 #include "nsRDFCID.h"
  32 #include "nsString.h"
  33 #include "nsXPIDLString.h"
  34 #include "nsUnicharUtils.h"
  35 #include "rdfutil.h"
  36
  37 ////////////////////////////////////////////////////////////////////////
  38
  39 nsresult
  40 rdf_MakeRelativeRef(const nsCSubstring& aBaseURI, nsCString& aURI)
  41 {
  42     // This implementation is extremely simple: e.g., it can't compute
  43     // relative paths, or anything fancy like that. If the context URI
  44     // is not a prefix of the URI in question, we'll just bail.
  45     uint32_t prefixLen = aBaseURI.Length();
  46     if (prefixLen != 0 && StringBeginsWith(aURI, aBaseURI)) {
  47         if (prefixLen < aURI.Length() && aURI.CharAt(prefixLen) == '/')
  48             ++prefixLen; // chop the leading slash so it's not `absolute'
  49
  50         aURI.Cut(0, prefixLen);
  51     }
  52
  53     return NS_OK;
  54 }
  55
  56 void
  57 rdf_FormatDate(PRTime aTime, nsACString &aResult)
  58 {
  59     // Outputs Unixish date in GMT plus usecs; e.g.,
  60     //   Wed Jan  9 19:15:13 2002 +002441
  61     //
  62     PRExplodedTime t;
  63     PR_ExplodeTime(aTime, PR_GMTParameters, &t);
  64
  65     char buf[256];
  66     PR_FormatTimeUSEnglish(buf, sizeof buf, "%a %b %d %H:%M:%S %Y", &t);
  67     aResult.Append(buf);
  68
  69     // usecs
  70     aResult.AppendLiteral(" +");
  71     int32_t usec = t.tm_usec;
  72     for (int32_t digit = 100000; digit > 1; digit /= 10) {
  73         aResult.Append(char('0' + (usec / digit)));
  74         usec %= digit;
  75     }
  76     aResult.Append(char('0' + usec));
  77 }
  78
  79 PRTime
  80 rdf_ParseDate(const nsACString &aTime)
  81 {
  82     PRTime t;
  83     PR_ParseTimeString(PromiseFlatCString(aTime).get(), true, &t);
  84
  85     int32_t usec = 0;
  86
  87     nsACString::const_iterator begin, digit, end;
  88     aTime.BeginReading(begin);
  89     aTime.EndReading(end);
  90
  91     // Walk backwards until we find a `+', run out of string, or a
  92     // non-numeric character.
  93     digit = end;
  94     while (--digit != begin && *digit != '+') {
  95         if (*digit < '0' || *digit > '9')
  96             break;
  97     }
  98
  99     if (digit != begin && *digit == '+') {
 100         // There's a usec field specified (or, at least, something
 101         // that looks close enough. Parse it, and add it to the time.
 102         while (++digit != end) {
 103             usec *= 10;
 104             usec += *digit - '0';
 105         }
 106
 107         t += usec;
 108     }
 109
 110     return t;
 111 }