From fdc5c8773cd929f189595157badb1736b21412ee Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Mon, 14 Apr 2014 17:17:54 -0400
Subject: [PATCH] Issue #7 - store MD5 of build command instead of the full
 command in the cache

---
 lib/rscons/cache.rb       |  8 ++++----
 spec/rscons/cache_spec.rb | 16 ++++++++--------
 2 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/lib/rscons/cache.rb b/lib/rscons/cache.rb
index d9d3e0b..0fc0da9 100644
--- a/lib/rscons/cache.rb
+++ b/lib/rscons/cache.rb
@@ -13,7 +13,7 @@ module Rscons
   #     "targets" => {
   #       "program" => {
   #         "checksum" => "A1B2C3D4",
-  #         "command" => ["gcc", "-o", "program", "program.o"],
+  #         "command" => "13543518FE",
   #         "deps" => [
   #           {
   #             "fname" => "program.o",
@@ -29,7 +29,7 @@ module Rscons
   #       },
   #       "program.o" => {
   #         "checksum" => "87654321",
-  #         "command" => ["gcc", "-c", "-o", "program.o", "program.c"],
+  #         "command" => "98765ABCD",
   #         "deps" => [
   #           {
   #             "fname" => "program.c",
@@ -118,7 +118,7 @@ module Rscons
         return false unless @cache["targets"][target]["checksum"] == lookup_checksum(target)
 
         # command used to build target must be identical
-        return false unless @cache["targets"][target]["command"] == command
+        return false unless @cache["targets"][target]["command"] == Digest::MD5.hexdigest(command.inspect)
 
         cached_deps = @cache["targets"][target]["deps"] || []
         cached_deps_fnames = cached_deps.map { |dc| dc["fname"] }
@@ -153,7 +153,7 @@ module Rscons
     def register_build(targets, command, deps, env)
       Array(targets).each do |target|
         @cache["targets"][target.encode(__ENCODING__)] = {
-          "command" => command,
+          "command" => Digest::MD5.hexdigest(command.inspect),
           "checksum" => calculate_checksum(target),
           "deps" => deps.map do |dep|
             {
diff --git a/spec/rscons/cache_spec.rb b/spec/rscons/cache_spec.rb
index 6a48d1f..a87e674 100644
--- a/spec/rscons/cache_spec.rb
+++ b/spec/rscons/cache_spec.rb
@@ -62,7 +62,7 @@ module Rscons
       end
 
       it "returns false when the build command has changed" do
-        _cache = {"targets" => {"target" => {"checksum" => "abc", "command" => "old command"}}}
+        _cache = {"targets" => {"target" => {"checksum" => "abc", "command" => Digest::MD5.hexdigest("old command".inspect)}}}
         cache = build_from(_cache)
         File.should_receive(:exists?).with("target").and_return(true)
         cache.should_receive(:calculate_checksum).with("target").and_return("abc")
@@ -71,7 +71,7 @@ module Rscons
 
       it "returns false when there is a new dependency" do
         _cache = {"targets" => {"target" => {"checksum" => "abc",
-                                         "command" => "command",
+                                         "command" => Digest::MD5.hexdigest("command".inspect),
                                          "deps" => [{"fname" => "dep.1"}]}}}
         cache = build_from(_cache)
         File.should_receive(:exists?).with("target").and_return(true)
@@ -81,7 +81,7 @@ module Rscons
 
       it "returns false when a dependency's checksum has changed" do
         _cache = {"targets" => {"target" => {"checksum" => "abc",
-                                         "command" => "command",
+                                         "command" => Digest::MD5.hexdigest("command".inspect),
                                          "deps" => [{"fname" => "dep.1",
                                                  "checksum" => "dep.1.chk"},
                                                 {"fname" => "dep.2",
@@ -99,7 +99,7 @@ module Rscons
 
       it "returns false with strict_deps=true when cache has an extra dependency" do
         _cache = {"targets" => {"target" => {"checksum" => "abc",
-                                         "command" => "command",
+                                         "command" => Digest::MD5.hexdigest("command".inspect),
                                          "deps" => [{"fname" => "dep.1",
                                                  "checksum" => "dep.1.chk"},
                                                 {"fname" => "dep.2",
@@ -115,7 +115,7 @@ module Rscons
 
       it "returns false when there is a new user dependency" do
         _cache = {"targets" => {"target" => {"checksum" => "abc",
-                                         "command" => "command",
+                                         "command" => Digest::MD5.hexdigest("command".inspect),
                                          "deps" => [{"fname" => "dep.1"}],
                                          "user_deps" => []}}}
         cache = build_from(_cache)
@@ -128,7 +128,7 @@ module Rscons
 
       it "returns false when a user dependency checksum has changed" do
         _cache = {"targets" => {"target" => {"checksum" => "abc",
-                                         "command" => "command",
+                                         "command" => Digest::MD5.hexdigest("command".inspect),
                                          "deps" => [{"fname" => "dep.1",
                                                  "checksum" => "dep.1.chk"},
                                                 {"fname" => "dep.2",
@@ -151,7 +151,7 @@ module Rscons
 
       it "returns true when no condition for false is met" do
         _cache = {"targets" => {"target" => {"checksum" => "abc",
-                                         "command" => "command",
+                                         "command" => Digest::MD5.hexdigest("command".inspect),
                                          "deps" => [{"fname" => "dep.1",
                                                  "checksum" => "dep.1.chk"},
                                                 {"fname" => "dep.2",
@@ -182,7 +182,7 @@ module Rscons
         cache.register_build("the target", "the command", ["dep 1", "dep 2"], env)
         cached_target = cache.instance_variable_get(:@cache)["targets"]["the target"]
         cached_target.should_not be_nil
-        cached_target["command"].should == "the command"
+        cached_target["command"].should == Digest::MD5.hexdigest("the command".inspect)
         cached_target["checksum"].should == "the checksum"
         cached_target["deps"].should == [
           {"fname" => "dep 1", "checksum" => "dep 1 checksum"},