Merge pull request #21 from obsidiansystems/undo-compareVersions-split

Revert "Move compareVersions to libutil"

src/libstore/ipfs-binary-cache-store.cc

@@ -4,7 +4,7 @@
 #include "binary-cache-store.hh"
 #include "filetransfer.hh"
 #include "nar-info-disk-cache.hh"
-#include "versions.hh"
+#include "names.hh"
 
 namespace nix {
 

src/libstore/names.cc

@@ -1,5 +1,5 @@
 #include "names.hh"
-#include "versions.hh"
+#include "util.hh"
 
 
 namespace nix {
@@ -41,6 +41,60 @@ bool DrvName::matches(DrvName & n)
 }
 
 
+string nextComponent(string::const_iterator & p,
+    const string::const_iterator end)
+{
+    /* Skip any dots and dashes (component separators). */
+    while (p != end && (*p == '.' || *p == '-')) ++p;
+
+    if (p == end) return "";
+
+    /* If the first character is a digit, consume the longest sequence
+       of digits.  Otherwise, consume the longest sequence of
+       non-digit, non-separator characters. */
+    string s;
+    if (isdigit(*p))
+        while (p != end && isdigit(*p)) s += *p++;
+    else
+        while (p != end && (!isdigit(*p) && *p != '.' && *p != '-'))
+            s += *p++;
+
+    return s;
+}
+
+
+static bool componentsLT(const string & c1, const string & c2)
+{
+    int n1, n2;
+    bool c1Num = string2Int(c1, n1), c2Num = string2Int(c2, n2);
+
+    if (c1Num && c2Num) return n1 < n2;
+    else if (c1 == "" && c2Num) return true;
+    else if (c1 == "pre" && c2 != "pre") return true;
+    else if (c2 == "pre") return false;
+    /* Assume that `2.3a' < `2.3.1'. */
+    else if (c2Num) return true;
+    else if (c1Num) return false;
+    else return c1 < c2;
+}
+
+
+int compareVersions(const string & v1, const string & v2)
+{
+    string::const_iterator p1 = v1.begin();
+    string::const_iterator p2 = v2.begin();
+
+    while (p1 != v1.end() || p2 != v2.end()) {
+        string c1 = nextComponent(p1, v1.end());
+        string c2 = nextComponent(p2, v2.end());
+        if (componentsLT(c1, c2)) return -1;
+        else if (componentsLT(c2, c1)) return 1;
+    }
+
+    return 0;
+}
+
+
 DrvNames drvNamesFromArgs(const Strings & opArgs)
 {
     DrvNames result;

src/libstore/names.hh

@@ -3,7 +3,6 @@
 #include <memory>
 
 #include "types.hh"
-#include "versions.hh"
 #include <regex>
 
 namespace nix {
@@ -25,6 +24,9 @@ private:
 
 typedef list<DrvName> DrvNames;
 
+string nextComponent(string::const_iterator & p,
+    const string::const_iterator end);
+int compareVersions(const string & v1, const string & v2);
 DrvNames drvNamesFromArgs(const Strings & opArgs);
 
 }