Add pruneblockchain RPC to enable manual block file pruning.

1 files changed, 10 insertions, 6 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 992ce8ebdc..9ac69b7d39 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -351,9 +351,9 @@ std::string HelpMessage(HelpMessageMode mode)
 #ifndef WIN32
     strUsage += HelpMessageOpt("-pid=<file>", strprintf(_("Specify pid file (default: %s)"), BITCOIN_PID_FILENAME));
 #endif
-    strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by pruning (deleting) old blocks. This mode is incompatible with -txindex and -rescan. "
+    strUsage += HelpMessageOpt("-prune=<n>", strprintf(_("Reduce storage requirements by enabling pruning (deleting) of old blocks. This allows the pruneblockchain RPC to be called to delete specific blocks, and enables automatic pruning of old blocks if a target size in MiB is provided. This mode is incompatible with -txindex and -rescan. "
             "Warning: Reverting this setting requires re-downloading the entire blockchain. "
-            "(default: 0 = disable pruning blocks, >%u = target size in MiB to use for block files)"), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
+            "(default: 0 = disable pruning blocks, 1 = allow manual pruning via RPC, >%u = automatically prune block files to stay under the specified target size in MiB)"), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
     strUsage += HelpMessageOpt("-reindex-chainstate", _("Rebuild chain state from the currently indexed blocks"));
     strUsage += HelpMessageOpt("-reindex", _("Rebuild chain state and block index from the blk*.dat files on disk"));
 #ifndef WIN32
@@ -936,12 +936,16 @@ bool AppInitParameterInteraction()
         nScriptCheckThreads = MAX_SCRIPTCHECK_THREADS;
 
     // block pruning; get the amount of disk space (in MiB) to allot for block & undo files
-    int64_t nSignedPruneTarget = GetArg("-prune", 0) * 1024 * 1024;
-    if (nSignedPruneTarget < 0) {
+    int64_t nPruneArg = GetArg("-prune", 0);
+    if (nPruneArg < 0) {
         return InitError(_("Prune cannot be configured with a negative value."));
     }
-    nPruneTarget = (uint64_t) nSignedPruneTarget;
-    if (nPruneTarget) {
+    nPruneTarget = (uint64_t) nPruneArg * 1024 * 1024;
+    if (nPruneArg == 1) {  // manual pruning: -prune=1
+        LogPrintf("Block pruning enabled.  Use RPC call pruneblockchain(height) to manually prune block and undo files.\n");
+        nPruneTarget = std::numeric_limits<uint64_t>::max();
+        fPruneMode = true;
+    } else if (nPruneTarget) {
         if (nPruneTarget < MIN_DISK_SPACE_FOR_BLOCK_FILES) {
             return InitError(strprintf(_("Prune configured below the minimum of %d MiB.  Please use a higher number."), MIN_DISK_SPACE_FOR_BLOCK_FILES / 1024 / 1024));
         }