rdf/base/src/rdfutil.cpp

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  37
  38 /*
  39
  40   Implementations for a bunch of useful RDF utility routines.  Many of
  41   these will eventually be exported outside of RDF.DLL via the
  42   nsIRDFService interface.
  43
  44   TO DO
  45
  46   1) Make this so that it doesn't permanently leak the RDF service
  47      object.
  48
  49   2) Make container functions thread-safe. They currently don't ensure
  50      that the RDF:nextVal property is maintained safely.
  51
  52  */
  53
  54 #include "nsCOMPtr.h"
  55 #include "nsIRDFDataSource.h"
  56 #include "nsIRDFNode.h"
  57 #include "nsIRDFService.h"
  58 #include "nsIServiceManager.h"
  59 #include "nsIURL.h"
  60 #include "nsIIOService.h"
  61 #include "nsIURL.h"
  62 #include "nsNetUtil.h"
  63 #include "nsRDFCID.h"
  64 #include "nsString.h"
  65 #include "nsXPIDLString.h"
  66 #include "nsUnicharUtils.h"
  67 #include "prtime.h"
  68 #include "rdfutil.h"
  69
  70 ////////////////////////////////////////////////////////////////////////
  71
  72 nsresult
  73 rdf_MakeRelativeRef(const nsCSubstring& aBaseURI, nsCString& aURI)
  74 {
  75     // This implementation is extremely simple: e.g., it can't compute
  76     // relative paths, or anything fancy like that. If the context URI
  77     // is not a prefix of the URI in question, we'll just bail.
  78     PRUint32 prefixLen = aBaseURI.Length();
  79     if (prefixLen != 0 && StringBeginsWith(aURI, aBaseURI)) {
  80         if (prefixLen < aURI.Length() && aURI.CharAt(prefixLen) == '/')
  81             ++prefixLen; // chop the leading slash so it's not `absolute'
  82
  83         aURI.Cut(0, prefixLen);
  84     }
  85
  86     return NS_OK;
  87 }
  88
  89 void
  90 rdf_FormatDate(PRTime aTime, nsACString &aResult)
  91 {
  92     // Outputs Unixish date in GMT plus usecs; e.g.,
  93     //   Wed Jan  9 19:15:13 2002 +002441
  94     //
  95     PRExplodedTime t;
  96     PR_ExplodeTime(aTime, PR_GMTParameters, &t);
  97
  98     char buf[256];
  99     PR_FormatTimeUSEnglish(buf, sizeof buf, "%a %b %d %H:%M:%S %Y", &t);
 100     aResult.Append(buf);
 101
 102     // usecs
 103     aResult.Append(" +");
 104     PRInt32 usec = t.tm_usec;
 105     for (PRInt32 digit = 100000; digit > 1; digit /= 10) {
 106         aResult.Append(char('0' + (usec / digit)));
 107         usec %= digit;
 108     }
 109     aResult.Append(char('0' + usec));
 110 }
 111
 112 PRTime
 113 rdf_ParseDate(const nsACString &aTime)
 114 {
 115     PRTime t;
 116     PR_ParseTimeString(PromiseFlatCString(aTime).get(), PR_TRUE, &t);
 117
 118     PRInt32 usec = 0;
 119
 120     nsACString::const_iterator begin, digit, end;
 121     aTime.BeginReading(begin);
 122     aTime.EndReading(end);
 123
 124     // Walk backwards until we find a `+', run out of string, or a
 125     // non-numeric character.
 126     digit = end;
 127     while (--digit != begin && *digit != '+') {
 128         if (*digit < '0' || *digit > '9')
 129             break;
 130     }
 131
 132     if (digit != begin && *digit == '+') {
 133         // There's a usec field specified (or, at least, something
 134         // that looks close enough. Parse it, and add it to the time.
 135         while (++digit != end) {
 136             usec *= 10;
 137             usec += *digit - '0';
 138         }
 139
 140         PRTime temp;
 141         LL_I2L(temp, usec);
 142         LL_ADD(t, t, temp);
 143     }
 144
 145     return t;
 146 }