Add --pause-metadata option

This option pauses downloads created as a result of metadata
download. There are 3 types of metadata downloads in aria2: (1)
downloading .torrent file. (2) downloading torrent metadata using
magnet link. (3) downloading metalink file.  These metadata downloads
will generate downloads using their metadata. This option pauses these
subsequent downloads.

doc/xmlrpc/aria2rpc

@@ -232,6 +232,7 @@ OptionParser.new do |opt|
   opt.on("--server-stat-of FILE"){|val| options["server-stat-of"]=val}
   opt.on("--save-cookies FILE"){|val| options["save-cookies"]=val}
   opt.on("--gid GID"){|val| options["gid"]=val}
+  opt.on("--pause-metadata [BOOL]",["true","false"]){|val| options["pause-metadata"]=val||"true"}
 
   opt.on("--server SERVER", "hostname of XML-RPC server. Default: localhost"){|val| options["server"]=val }
   opt.on("--port PORT", "port of XML-RPC server. Default: 6800"){|val| options["port"]=val }

src/BtPostDownloadHandler.cc

@@ -52,6 +52,7 @@
 #include "DiskWriter.h"
 #include "AbstractSingleDiskAdaptor.h"
 #include "BencodeDiskWriter.h"
+#include "RequestGroupMan.h"
 
 namespace aria2 {
 
@@ -108,6 +109,16 @@ void BtPostDownloadHandler::getNextRequestGroups
   if(mi) {
     setMetadataInfo(newRgs.begin(), newRgs.end(), mi);
   }
+
+  auto rgman = requestGroup->getRequestGroupMan();
+
+  if(rgman && rgman->getKeepRunning() &&
+     requestGroup->getOption()->getAsBool(PREF_PAUSE_METADATA)) {
+    for(auto& rg : newRgs) {
+      rg->setPauseRequested(true);
+    }
+  }
+
   groups.insert(groups.end(), newRgs.begin(), newRgs.end());
 }
 

src/MetalinkPostDownloadHandler.cc

@@ -51,6 +51,7 @@
 #include "download_helper.h"
 #include "fmt.h"
 #include "FileEntry.h"
+#include "RequestGroupMan.h"
 
 namespace aria2 {
 
@@ -105,6 +106,16 @@ void MetalinkPostDownloadHandler::getNextRequestGroups
     if(mi) {
       setMetadataInfo(newRgs.begin(), newRgs.end(), mi);
     }
+
+    auto rgman = requestGroup->getRequestGroupMan();
+
+    if(rgman && rgman->getKeepRunning() &&
+       requestGroup->getOption()->getAsBool(PREF_PAUSE_METADATA)) {
+      for(auto& rg : newRgs) {
+        rg->setPauseRequested(true);
+      }
+    }
+
     groups.insert(groups.end(), newRgs.begin(), newRgs.end());
     diskAdaptor->closeFile();
   } catch(Exception& e) {

src/OptionHandlerFactory.cc

@@ -679,6 +679,19 @@ std::vector<OptionHandler*> OptionHandlerFactory::createOptionHandlers()
     op->setInitialOption(true);
     handlers.push_back(op);
   }
+  {
+    OptionHandler* op(new BooleanOptionHandler
+                      (PREF_PAUSE_METADATA,
+                       TEXT_PAUSE_METADATA,
+                       A2_V_FALSE,
+                       OptionHandler::OPT_ARG));
+    op->addTag(TAG_ADVANCED);
+    op->addTag(TAG_RPC);
+    op->setInitialOption(true);
+    op->setChangeGlobalOption(true);
+    op->setChangeOptionForReserved(true);
+    handlers.push_back(op);
+  }
   {
     OptionHandler* op(new BooleanOptionHandler
                       (PREF_QUIET,

src/UTMetadataPostDownloadHandler.cc

@@ -50,6 +50,7 @@
 #include "prefs.h"
 #include "Option.h"
 #include "fmt.h"
+#include "RequestGroupMan.h"
 
 namespace aria2 {
 
@@ -107,6 +108,16 @@ void UTMetadataPostDownloadHandler::getNextRequestGroups
       setMetadataInfo(newRgs.begin(), newRgs.end(),
                       requestGroup->getMetadataInfo());
     }
+
+    auto rgman = requestGroup->getRequestGroupMan();
+
+    if(rgman && rgman->getKeepRunning() &&
+       requestGroup->getOption()->getAsBool(PREF_PAUSE_METADATA)) {
+      for(auto& rg : newRgs) {
+        rg->setPauseRequested(true);
+      }
+    }
+
     groups.insert(groups.end(), newRgs.begin(), newRgs.end());
   }
 }

src/prefs.cc

@@ -363,6 +363,8 @@ PrefPtr PREF_ENABLE_COLOR = makePref("enable-color");
 PrefPtr PREF_RPC_SECRET = makePref("rpc-secret");
 // values: 1*digit
 PrefPtr PREF_DSCP = makePref("dscp");
+// values: true | false
+PrefPtr PREF_PAUSE_METADATA = makePref("pause-metadata");
 
 /**
  * FTP related preferences

src/prefs.h

@@ -300,6 +300,8 @@ extern PrefPtr PREF_ENABLE_COLOR;
 extern PrefPtr PREF_RPC_SECRET;
 // values: 1*digit
 extern PrefPtr PREF_DSCP;
+// values: true | false
+extern PrefPtr PREF_PAUSE_METADATA;
 
 /**
  * FTP related preferences

src/usage_text.h

@@ -980,3 +980,14 @@
     "                              commonly used values from RFC, network vendors'\n" \
     "                              documentation, Wikipedia or any other source,\n" \
     "                              use them as they are.")
+#define TEXT_PAUSE_METADATA                  \
+  _(" --pause-metadata[=true|false]\n"       \
+    "                              Pause downloads created as a result of metadata\n" \
+    "                              download. There are 3 types of metadata\n" \
+    "                              downloads in aria2: (1) downloading .torrent\n" \
+    "                              file. (2) downloading torrent metadata using\n" \
+    "                              magnet link. (3) downloading metalink file.\n" \
+    "                              These metadata downloads will generate downloads\n" \
+    "                              using their metadata. This option pauses these\n" \
+    "                              subsequent downloads. This option is effective\n" \
+    "                              only when --enable-rpc=true is given.")