From d7d59b08a2f1a77a4247ec1a89d6ff48ed73f5c7 Mon Sep 17 00:00:00 2001
From: James Turner <zakalawe@mac.com>
Date: Thu, 18 Aug 2016 16:21:31 +0100
Subject: [PATCH] Copy-from-install support in TerraSync

Allows repositories to be initialised based on data in the install.
This avoids duplicate downloading of the Model and Airport data,
and the starting scenery.

Requires a corresponding FlightGear change to be functional.
---
 simgear/io/HTTPRepository.cxx     | 56 +++++++++++++++++++++++++++++++
 simgear/io/HTTPRepository.hxx     |  6 ++++
 simgear/scene/tsync/terrasync.cxx | 12 +++++++
 3 files changed, 74 insertions(+)

diff --git a/simgear/io/HTTPRepository.cxx b/simgear/io/HTTPRepository.cxx
index 6a631423..d36117be 100644
--- a/simgear/io/HTTPRepository.cxx
+++ b/simgear/io/HTTPRepository.cxx
@@ -150,6 +150,7 @@ public:
     typedef std::vector<HTTPDirectory*> DirectoryVector;
     DirectoryVector directories;
 
+    SGPath installedCopyPath;
 };
 
 class HTTPDirectory
@@ -255,6 +256,54 @@ public:
         }
     }
 
+    void copyInstalledChildren()
+    {
+        if (_repository->installedCopyPath.isNull()) {
+            return;
+        }
+        
+        string_list indexNames = indexChildren();
+        const_string_list_iterator nameIt = indexNames.begin();
+        for (; nameIt != indexNames.end(); ++nameIt) {
+            SGPath p(absolutePath());
+            p.append(*nameIt);
+            if (p.exists()) {
+                continue; // only copy if the file is missing entirely
+            }
+
+            ChildInfoList::iterator c = findIndexChild(*nameIt);
+            if (c->type == ChildInfo::DirectoryType) {
+                continue; // only care about files
+            }
+
+            SGPath cp = _repository->installedCopyPath;
+            cp.append(relativePath());
+            cp.append(*nameIt);
+            if (!cp.exists()) {
+                continue;
+            }
+
+            SG_LOG(SG_TERRASYNC, SG_BULK, "new child, copying existing file" << cp << p);
+            
+            SGBinaryFile src(cp);
+            SGBinaryFile dst(p);
+            src.open(SG_IO_IN);
+            dst.open(SG_IO_OUT);
+
+            char* buf = (char*) malloc(cp.sizeInBytes());
+            if (!buf) {
+                continue;
+            }
+
+            src.read(buf, cp.sizeInBytes());
+            dst.write(buf, cp.sizeInBytes());
+            src.close();
+            dst.close();
+
+            free(buf);
+        }
+    }
+
     void updateChildrenBasedOnHash()
     {
         // if we got here for a dir which is still updating or excluded
@@ -263,6 +312,8 @@ public:
             return;
         }
 
+        copyInstalledChildren();
+
         string_list indexNames = indexChildren(),
             toBeUpdated, orphans;
         simgear::Dir d(absolutePath());
@@ -723,6 +774,11 @@ size_t HTTPRepository::bytesDownloaded() const
     return result;
 }
 
+void HTTPRepository::setInstalledCopyPath(const SGPath& copyPath)
+{
+    _d->installedCopyPath = copyPath;
+}
+
 HTTPRepository::ResultCode
 HTTPRepository::failure() const
 {
diff --git a/simgear/io/HTTPRepository.hxx b/simgear/io/HTTPRepository.hxx
index 7d46c3dd..a46ba083 100644
--- a/simgear/io/HTTPRepository.hxx
+++ b/simgear/io/HTTPRepository.hxx
@@ -71,6 +71,12 @@ public:
     virtual size_t bytesToDownload() const;
 
     virtual size_t bytesDownloaded() const;
+
+    /**
+     * optionally provide the location of an installer copy of this
+     * repository. When a file is missing it will be copied from this tree.
+     */
+    void setInstalledCopyPath(const SGPath& copyPath);
 private:
     bool isBare() const;
 
diff --git a/simgear/scene/tsync/terrasync.cxx b/simgear/scene/tsync/terrasync.cxx
index df660d86..1f3f8d2b 100644
--- a/simgear/scene/tsync/terrasync.cxx
+++ b/simgear/scene/tsync/terrasync.cxx
@@ -274,6 +274,8 @@ public:
    void   setLocalDir(string dir)           { _local_dir    = stripPath(dir);}
    string getLocalDir()                     { return _local_dir;}
 
+    void setInstalledDir(const SGPath& p)  { _installRoot = p; }
+
    void   setAllowedErrorCount(int errors)
     {
         SGGuard<SGMutex> g(_stateLock);
@@ -331,6 +333,7 @@ private:
    string _local_dir;
    SGPath _persistentCachePath;
    string _httpServer;
+    SGPath _installRoot;
 
     TerrasyncThreadState _state;
     SGMutex _stateLock;
@@ -547,6 +550,12 @@ void SGTerraSync::WorkerThread::updateSyncSlot(SyncSlot &slot)
         slot.repository->setEntireRepositoryMode();
         slot.repository->setBaseUrl(_httpServer + "/" + slot.currentItem._dir);
 
+        if (_installRoot.exists()) {
+            SGPath p = _installRoot;
+            p.append(slot.currentItem._dir);
+            slot.repository->setInstalledCopyPath(p);
+        }
+
         try {
             slot.repository->update();
         } catch (sg_exception& e) {
@@ -825,6 +834,9 @@ void SGTerraSync::reinit()
         std::string httpServer(_terraRoot->getStringValue("http-server",""));
         _workerThread->setHTTPServer(httpServer);
         _workerThread->setLocalDir(_terraRoot->getStringValue("scenery-dir",""));
+
+        SGPath installPath(_terraRoot->getStringValue("installation-dir"));
+        _workerThread->setInstalledDir(installPath);
         _workerThread->setAllowedErrorCount(_terraRoot->getIntValue("max-errors",5));
         _workerThread->setCacheHits(_terraRoot->getIntValue("cache-hit", 0));