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authorEelco Dolstra <e.dolstra@tudelft.nl>2006-12-12T23·05+0000
committerEelco Dolstra <e.dolstra@tudelft.nl>2006-12-12T23·05+0000
commita3e6415ba8cf1b8d2a1db40c06997d997eac8afc (patch)
tree16e43edf9a785101b562ee3bfa6cbaeb600fc22a /src/libutil/serialise.hh
parentb438d37558eab56a2927771013c9080675381ba8 (diff)
* New primop builtins.filterSource, which can be used to filter files
  from a source directory.  All files for which a predicate function
  returns true are copied to the store.  Typical example is to leave
  out the .svn directory:

    stdenv.mkDerivation {
      ...
      src = builtins.filterSource
        (path: baseNameOf (toString path) != ".svn")
        ./source-dir;
      # as opposed to
      #   src = ./source-dir;
    }

  This is important because the .svn directory influences the hash in
  a rather unpredictable and variable way.

Diffstat (limited to 'src/libutil/serialise.hh')
-rw-r--r--src/libutil/serialise.hh27
1 files changed, 27 insertions, 0 deletions
diff --git a/src/libutil/serialise.hh b/src/libutil/serialise.hh
index fe3492235e97..c18e82463b5a 100644
--- a/src/libutil/serialise.hh
+++ b/src/libutil/serialise.hh
@@ -66,6 +66,33 @@ struct FdSource : Source
 };
 
 
+/* A sink that writes data to a string. */
+struct StringSink : Sink
+{
+    string s;
+    virtual void operator () (const unsigned char * data, unsigned int len)
+    {
+        s.append((const char *) data, len);
+    }
+};
+
+
+/* A source that reads data from a string. */
+struct StringSource : Source
+{
+    string & s;
+    unsigned int pos;
+    StringSource(string & _s) : s(_s), pos(0) { }
+    virtual void operator () (unsigned char * data, unsigned int len)
+    {
+        s.copy((char *) data, len, pos);
+        pos += len;
+        if (pos > s.size())
+            throw Error("end of string reached");
+    }
+};
+
+
 void writePadding(unsigned int len, Sink & sink);
 void writeInt(unsigned int n, Sink & sink);
 void writeString(const string & s, Sink & sink);