6 files changed, 74 insertions, 6 deletions

diff --git a/src/cache.cpp b/src/cache.cpp
index 1646d0a..de505b8 100644
--- a/src/cache.cpp
+++ b/src/cache.cpp
@@ -1,14 +1,18 @@
 #include "cache.h"
 #include <bu/file.h>
 #include <bu/archive.h>
+#include <bu/sio.h>
+using namespace Bu;
 
 Cache::Cache() :
+        bCacheChanged( false ),
         bIsLoaded( false )
 {
 }
 
 Cache::~Cache()
 {
+        save();
 }
 
 void Cache::bind( const Bu::FString &sCacheFile )
@@ -21,19 +25,40 @@ void Cache::load()
 {
         if( bIsLoaded )
                 return;
-        Bu::File fIn( sCacheFile, Bu::File::Read );
-        Bu::Archive ar( fIn, Bu::Archive::load );
 
-        ar >> hRequires >> hVariables;
+        try
+        {
+                Bu::File fIn( sCacheFile, Bu::File::Read );
+                Bu::Archive ar( fIn, Bu::Archive::load );
+
+                ar >> hRequires >> hVariables;
+        }
+        catch(...) { }
 
         bIsLoaded = true;
 }
 
 void Cache::save()
 {
+        if( !bIsLoaded )
+                return;
+        if( bCacheChanged == false )
+                return;
+
         Bu::File fIn( sCacheFile, Bu::File::WriteNew );
         Bu::Archive ar( fIn, Bu::Archive::save );
 
         ar << hRequires << hVariables;
 }
 
+StrList Cache::getRequires( const Bu::FString &sOutput )
+{
+        return hRequires.get( sOutput );
+}
+
+void Cache::setRequires( const Bu::FString &sOutput, StrList lReqs )
+{
+        hRequires.insert( sOutput, lReqs );
+        bCacheChanged = true;
+}
+
diff --git a/src/cache.h b/src/cache.h
index 31da981..8932091 100644
--- a/src/cache.h
+++ b/src/cache.h
@@ -7,6 +7,7 @@
 #include <bu/list.h>
 
 #include "variable.h"
+#include "types.h"
 
 class Cache : public Bu::Singleton<Cache>
 {
@@ -21,12 +22,14 @@ public:
         void load();
         void save();
 
-
+        StrList getRequires( const Bu::FString &sOutput );
+        void setRequires( const Bu::FString &sOutput, StrList lReqs );
 
 private:
+        bool bCacheChanged;
         Bu::FString sCacheFile;
         bool bIsLoaded;
-        typedef Bu::Hash<Bu::FString, Bu::List<Bu::FString> > ReqHash;
+        typedef Bu::Hash<Bu::FString, StrList> ReqHash;
         ReqHash hRequires;
         typedef Bu::Hash<Bu::FString, Variable> VarHash;
         VarHash hVariables;
diff --git a/src/conditionfiletime.cpp b/src/conditionfiletime.cpp
index 224caf1..148ffac 100644
--- a/src/conditionfiletime.cpp
+++ b/src/conditionfiletime.cpp
@@ -25,6 +25,7 @@ bool ConditionFileTime::shouldExec( class Runner &r, Target &rTarget )
                         //sio << "-- Target processed because '" << *j << "' doesn't exist."
                         //      << sio.nl;
                         // Output doesn't exist
+                        rTarget.buildRequires( r );
                         return true;
                 }
         }
@@ -48,10 +49,11 @@ bool ConditionFileTime::shouldExec( class Runner &r, Target &rTarget )
                 {
                         //sio << "-- Target processed because '" << *j
                         //      << "' is newer than output." << sio.nl;
+                        rTarget.buildRequires( r );
                         return true;
                 }
         }
-        rTarget.buildRequires( r );
+        rTarget.gatherRequires( r );
         for( StrList::const_iterator j = rTarget.getRequiresList().begin();
                  j; j++ )
         {
@@ -60,6 +62,7 @@ bool ConditionFileTime::shouldExec( class Runner &r, Target &rTarget )
                 {
                         //sio << "-- Target processed because '" << *j
                         //      << "' is newer than output." << sio.nl;
+                        rTarget.buildRequires( r );
                         return true;
                 }
         }
diff --git a/src/main.cpp b/src/main.cpp
index 142927d..1bed895 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -6,6 +6,8 @@
 
 #include "viewplugger.h"
 
+#include "cache.h"
+
 #include <bu/optparser.h>
 #include <bu/sio.h>
 #include <sys/types.h>
@@ -24,11 +26,13 @@ public:
                 sView("default"),
                 sAction("default"),
                 sConfig("default.bld"),
+                sCacheFile(".build_cache"),
                 bDot( false ),
                 bDebug( false ),
                 bAutoInclude( true ),
                 bAstDump( false ),
                 bEnviron( true ),
+                bCache( true ),
                 iInfoLevel( 0 )
         {
                 bool bClean = false;
@@ -54,6 +58,8 @@ public:
                         "action is specified, this will modify it to run 'clean-action'.");
                 addOption( slot(this, &Options::onChdir), 'C', "chdir",
                         "Change to directory before doing anything else.");
+                addOption( sCacheFile, "cache", "Select a different cache file.");
+                addOption( bCache, "no-cache", "Disable using the cache.");
 
                 addHelpBanner("\nThe following options control debugging:");
                 addOption( bEnviron, "no-env", "Do not import environment variables.");
@@ -71,6 +77,7 @@ public:
                 setOverride( "debug-ast", "true" );
                 setOverride( "info", "1" );
                 setOverride( 'c', "true" );
+                setOverride( "no-cache", "false" );
 
                 addHelpOption();
 
@@ -111,11 +118,13 @@ public:
         Bu::FString sView;
         Bu::FString sAction;
         Bu::FString sConfig;
+        Bu::FString sCacheFile;
         bool bDot;
         bool bDebug;
         bool bAutoInclude;
         bool bAstDump;
         bool bEnviron;
+        bool bCache;
         int iInfoLevel;
 };
 
@@ -155,6 +164,11 @@ int main( int argc, char *argv[] )
                 return 1;
         }
 
+        if( opts.bCache )
+        {
+                Cache::getInstance().bind( opts.sCacheFile );
+        }
+
         // Load up the environment as vars.
         if( opts.bEnviron )
         {
diff --git a/src/target.cpp b/src/target.cpp
index 1846044..4f9dd77 100644
--- a/src/target.cpp
+++ b/src/target.cpp
@@ -7,6 +7,7 @@
 #include "context.h"
 #include "profile.h"
 #include "view.h"
+#include "cache.h"
 
 #include <bu/membuf.h>
 #include <bu/formatter.h>
@@ -76,6 +77,19 @@ const StrList &Target::getRequiresList() const
         return lsRequires;
 }
 
+void Target::gatherRequires( Runner &r )
+{
+        Cache &c = Cache::getInstance();
+        try
+        {
+                lsRequires = c.getRequires( lsOutput.first() );
+        }
+        catch( Bu::HashException &e )
+        {
+                buildRequires( r );
+        }
+}
+
 void Target::buildRequires( Runner &r )
 {
         r.getContext().getView()->buildRequires( *this );
@@ -108,6 +122,9 @@ void Target::buildRequires( Runner &r )
                 }
         }
         r.getContext().popScope();
+
+        Cache &c = Cache::getInstance();
+        c.setRequires( lsOutput.first(), lsRequires );
 }
 
 void Target::addOutput( const Bu::FString &sOutput )
diff --git a/src/target.h b/src/target.h
index 766366a..25af1f4 100644
--- a/src/target.h
+++ b/src/target.h
@@ -19,6 +19,12 @@ public:
         void addRequires( const Bu::FString &sReq );
         void addRequires( const AstBranch *pBr );
         const StrList &getRequiresList() const;
+        /**
+         * This function will get the cached requires if they exist, build them
+         * if they don't.  Use this is conditions, but use buildRequires to force
+         * a rebuild even if cached data exists.
+         */
+        void gatherRequires( class Runner &r );
         void buildRequires( class Runner &r );
 
         void addOutput( const Bu::FString &sOutput );