move implementation of checksums around by abstracting even more

[apt.git] / apt-pkg / contrib / hashsum.cc

diff --git a/apt-pkg/contrib/hashsum.cc b/apt-pkg/contrib/hashsum.cc
new file mode 100644 (file)
index 0000000..b97eaf8
--- /dev/null
+++ b/apt-pkg/contrib/hashsum.cc
@@ -0,0 +1,28 @@
+// Cryptographic API Base
+
+#include <unistd.h>
+#include "hashsum_template.h"
+
+// Summation::AddFD - Add content of file into the checksum            /*{{{*/
+// ---------------------------------------------------------------------
+/* */
+bool SummationImplementation::AddFD(int const Fd, unsigned long Size) {
+   unsigned char Buf[64 * 64];
+   int Res = 0;
+   int ToEOF = (Size == 0);
+   unsigned long n = sizeof(Buf);
+   if (!ToEOF)
+      n = std::min(Size, n);
+   while (Size != 0 || ToEOF)
+   {
+      Res = read(Fd, Buf, n);
+      if (Res < 0 || (!ToEOF && (unsigned) Res != n)) // error, or short read
+        return false;
+      if (ToEOF && Res == 0) // EOF
+        break;
+      Size -= Res;
+      Add(Buf,Res);
+   }
+   return true;
+}
+                                                                       /*}}}*/