Add changePosition API

6 files changed, 78 insertions, 20 deletions

diff --git a/src/IndexedList.h b/src/IndexedList.h
index abccf295..0a259225 100644
--- a/src/IndexedList.h
+++ b/src/IndexedList.h
@@ -42,13 +42,9 @@
 #include <vector>
 #include <algorithm>
 
-namespace aria2 {
+#include <aria2/aria2.h>
 
-enum A2_HOW {
-  A2_POS_SET,
-  A2_POS_CUR,
-  A2_POS_END
-};
+namespace aria2 {
 
 template<typename SeqType, typename ValueType, typename ReferenceType,
          typename PointerType, typename SeqIteratorType>
@@ -539,15 +535,15 @@ public:
   }
 
   // Moves element with |key| to the specified position. If |how| is
-  // A2_POS_CUR, the element is moved to the position |offset|
-  // relative to the current position. If |how| is A2_POS_SET, the
-  // element is moved to the position |offset|. If |how| is
-  // A2_POS_END, the element is moved to the position |offset|
+  // OFFSET_MODE_CUR, the element is moved to the position |offset|
+  // relative to the current position. If |how| is OFFSET_MODE_SET,
+  // the element is moved to the position |offset|. If |how| is
+  // OFFSET_MODE_END, the element is moved to the position |offset|
   // relative to the end of the list.  This function returns the
   // position the elment is moved to if it succeeds, or -1 if no
   // element with |key| is found or |how| is invalid.  Complexity:
   // O(N)
-  ssize_t move(KeyType key, ssize_t offset, A2_HOW how)
+  ssize_t move(KeyType key, ssize_t offset, OffsetMode how)
   {
     typename IndexType::iterator idxent = index_.find(key);
     if(idxent == index_.end()) {
@@ -562,16 +558,16 @@ public:
     ssize_t xp = std::distance(seq_.begin(), x);
     ssize_t size = index_.size();
     ssize_t dest;
-    if(how == A2_POS_CUR) {
+    if(how == OFFSET_MODE_CUR) {
       if(offset > 0) {
         dest = std::min(xp+offset, static_cast<ssize_t>(size-1));
       } else {
         dest = std::max(xp+offset, static_cast<ssize_t>(0));
       }
     } else {
-      if(how == A2_POS_END) {
+      if(how == OFFSET_MODE_END) {
         dest = std::min(size-1+offset, size-1);
-      } else if(how == A2_POS_SET) {
+      } else if(how == OFFSET_MODE_SET) {
         dest = std::min(offset, size-1);
       } else {
         return -1;
diff --git a/src/RequestGroupMan.cc b/src/RequestGroupMan.cc
index 3fdf064f..60ededbb 100644
--- a/src/RequestGroupMan.cc
+++ b/src/RequestGroupMan.cc
@@ -192,7 +192,7 @@ SharedHandle<RequestGroup> RequestGroupMan::findGroup(a2_gid_t gid) const
 }
 
 size_t RequestGroupMan::changeReservedGroupPosition
-(a2_gid_t gid, int pos, A2_HOW how)
+(a2_gid_t gid, int pos, OffsetMode how)
 {
   ssize_t dest = reservedGroups_.move(gid, pos, how);
   if(dest == -1) {
diff --git a/src/RequestGroupMan.h b/src/RequestGroupMan.h
index 186ed379..ab595372 100644
--- a/src/RequestGroupMan.h
+++ b/src/RequestGroupMan.h
@@ -180,7 +180,7 @@ public:
   // beginning or the end of the queue respectively.  Returns the
   // destination position.
   size_t changeReservedGroupPosition(a2_gid_t gid, int pos,
-                                     A2_HOW how);
+                                     OffsetMode how);
 
   bool removeReservedGroup(a2_gid_t gid);
 
diff --git a/src/RpcMethodImpl.cc b/src/RpcMethodImpl.cc
index 3c7f386f..c88753f7 100644
--- a/src/RpcMethodImpl.cc
+++ b/src/RpcMethodImpl.cc
@@ -1301,13 +1301,13 @@ SharedHandle<ValueBase> ChangePositionRpcMethod::process
   a2_gid_t gid = str2Gid(gidParam);
   int pos = posParam->i();
   const std::string& howStr = howParam->s();
-  A2_HOW how;
+  OffsetMode how;
   if(howStr == "POS_SET") {
-    how = A2_POS_SET;
+    how = OFFSET_MODE_SET;
   } else if(howStr == "POS_CUR") {
-    how = A2_POS_CUR;
+    how = OFFSET_MODE_CUR;
   } else if(howStr == "POS_END") {
-    how = A2_POS_END;
+    how = OFFSET_MODE_END;
   } else {
     throw DL_ABORT_EX("Illegal argument.");
   }
diff --git a/src/aria2api.cc b/src/aria2api.cc
index 2e4702ff..cd4eec59 100644
--- a/src/aria2api.cc
+++ b/src/aria2api.cc
@@ -367,6 +367,18 @@ int unpauseDownload(Session* session, const A2Gid& gid)
   return 0;
 }
 
+int changePosition(Session* session, const A2Gid& gid, int pos, OffsetMode how)
+{
+  const SharedHandle<DownloadEngine>& e =
+    session->context->reqinfo->getDownloadEngine();
+  try {
+    return e->getRequestGroupMan()->changeReservedGroupPosition(gid, pos, how);
+  } catch(RecoverableException& e) {
+    A2_LOG_INFO_EX(EX_EXCEPTION_CAUGHT, e);
+    return -1;
+  }
+}
+
 std::vector<A2Gid> getActiveDownload(Session* session)
 {
   const SharedHandle<DownloadEngine>& e =
diff --git a/src/includes/aria2/aria2.h b/src/includes/aria2/aria2.h
index 94ebe427..46281a66 100644
--- a/src/includes/aria2/aria2.h
+++ b/src/includes/aria2/aria2.h
@@ -362,6 +362,56 @@ int pauseDownload(Session* session, const A2Gid& gid, bool force = false);
 int unpauseDownload(Session* session, const A2Gid& gid);
 
 /**
+ * @enum
+ *
+ * Constants how to re-position a download.
+ */
+enum OffsetMode {
+  /**
+   * Moves the download to a position relative to the beginning of the
+   * queue.
+   */
+  OFFSET_MODE_SET,
+  /**
+   * Moves the download to a position relative to the current
+   * position.
+   */
+  OFFSET_MODE_CUR,
+  /**
+   * Moves the download to a position relative to the end of the
+   * queue.
+   */
+  OFFSET_MODE_END
+};
+
+/**
+ * @function
+ *
+ * Changes the position of the download denoted by the |gid|. if it is
+ * in :c:macro:`DOWNLOAD_WAITING` or :c:macro:`DOWNLOAD_PAUSED` state.
+ * If the |how| is :c:macro:`OFFSET_MODE_SET`, it moves the download
+ * to a position |pos| relative to the beginning of the queue. If the
+ * |how| is :c:macro:`OFFSET_MODE_CUR`, it moves the download to a
+ * position |pos| relative to the current position. If the |how| is
+ * :c:macro:`OFFSET_MODE_END`, it moves the download to a position
+ * |pos| relative to the end of the queue. If the destination position
+ * is less than 0 or beyond the end of the queue, it moves the
+ * download to the beginning or the end of the queue respectively. The
+ * response is the destination position on success.
+ *
+ * For example, if the download having GID gid is placed in position
+ * 3, ``changePosition(gid, -1, OFFSET_MODE_CUR)`` will change its
+ * position to 2. Additional call ``changePosition(gid, 0,
+ * OFFSET_MODE_SET)`` will change its position to 0 (the beginning of
+ * the queue).
+ *
+ * This function returns the final destination position of this
+ * download, or negative error code.
+ */
+int changePosition(Session* session, const A2Gid& gid, int pos,
+                   OffsetMode how);
+
+/**
  * @function
  *
  * Schedules shutdown. If the |force| is true, shutdown will take