Merge #12653: Allow to optional specify the directory for the blocks storage

a192636 -blocksdir: keep blockindex leveldb database in datadir (Jonas Schnelli)
f38e4fd QA: Add -blocksdir test (Jonas Schnelli)
386a6b6 Allow to optional specify the directory for the blocks storage (Jonas Schnelli)

Pull request description:

  Since the actual block files taking up more and more space, it may be desirable to have them stored in a different location then the data directory (use case: SSD for chainstate, etc., HD for blocks).

  This PR adds a `-blocksdir` option that allows one to keep the blockfiles and the blockindex external from the data directory (instead of creating symlinks).

  I fist had an option to keep the blockindex within the datadir, but seems to make no sense since accessing the index will (always) lead to access (r/w) the block files.

Tree-SHA512: f8b9e1a681679eac25076dc30e45e6e12d4b2d9ac4be907cbea928a75af081dbcb0f1dd3e97169ab975f73d0bd15824c00c2a34638f3b284b39017171fce2409

1 files changed, 6 insertions, 6 deletions

diff --git a/src/validation.cpp b/src/validation.cpp
index a85ea3ddd5..d107fec70c 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -2108,7 +2108,7 @@ bool static FlushStateToDisk(const CChainParams& chainparams, CValidationState &
         // Write blocks and block index to disk.
         if (fDoFullFlush || fPeriodicWrite) {
             // Depend on nMinDiskSpace to ensure we can write block index
-            if (!CheckDiskSpace(0))
+            if (!CheckDiskSpace(0, true))
                 return state.Error("out of disk space");
             // First make sure all block and undo data is flushed to disk.
             FlushBlockFile();
@@ -2953,7 +2953,7 @@ static bool FindBlockPos(CDiskBlockPos &pos, unsigned int nAddSize, unsigned int
         if (nNewChunks > nOldChunks) {
             if (fPruneMode)
                 fCheckForPruning = true;
-            if (CheckDiskSpace(nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos)) {
+            if (CheckDiskSpace(nNewChunks * BLOCKFILE_CHUNK_SIZE - pos.nPos, true)) {
                 FILE *file = OpenBlockFile(pos);
                 if (file) {
                     LogPrintf("Pre-allocating up to position 0x%x in blk%05u.dat\n", nNewChunks * BLOCKFILE_CHUNK_SIZE, pos.nFile);
@@ -2986,7 +2986,7 @@ static bool FindUndoPos(CValidationState &state, int nFile, CDiskBlockPos &pos,
     if (nNewChunks > nOldChunks) {
         if (fPruneMode)
             fCheckForPruning = true;
-        if (CheckDiskSpace(nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos)) {
+        if (CheckDiskSpace(nNewChunks * UNDOFILE_CHUNK_SIZE - pos.nPos, true)) {
             FILE *file = OpenUndoFile(pos);
             if (file) {
                 LogPrintf("Pre-allocating up to position 0x%x in rev%05u.dat\n", nNewChunks * UNDOFILE_CHUNK_SIZE, pos.nFile);
@@ -3661,9 +3661,9 @@ static void FindFilesToPrune(std::set<int>& setFilesToPrune, uint64_t nPruneAfte
            nLastBlockWeCanPrune, count);
 }
 
-bool CheckDiskSpace(uint64_t nAdditionalBytes)
+bool CheckDiskSpace(uint64_t nAdditionalBytes, bool blocks_dir)
 {
-    uint64_t nFreeBytesAvailable = fs::space(GetDataDir()).available;
+    uint64_t nFreeBytesAvailable = fs::space(blocks_dir ? GetBlocksDir() : GetDataDir()).available;
 
     // Check for nMinDiskSpace bytes (currently 50MB)
     if (nFreeBytesAvailable < nMinDiskSpace + nAdditionalBytes)
@@ -3706,7 +3706,7 @@ static FILE* OpenUndoFile(const CDiskBlockPos &pos, bool fReadOnly) {
 
 fs::path GetBlockPosFilename(const CDiskBlockPos &pos, const char *prefix)
 {
-    return GetDataDir() / "blocks" / strprintf("%s%05u.dat", prefix, pos.nFile);
+    return GetBlocksDir() / strprintf("%s%05u.dat", prefix, pos.nFile);
 }
 
 CBlockIndex * CChainState::InsertBlockIndex(const uint256& hash)