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, 7 insertions, 2 deletions

diff --git a/src/init.cpp b/src/init.cpp
index 5447c15009..b0ba0cb835 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -333,6 +333,7 @@ std::string HelpMessage(HelpMessageMode mode)
     strUsage += HelpMessageOpt("-version", _("Print version and exit"));
     strUsage += HelpMessageOpt("-alertnotify=<cmd>", _("Execute command when a relevant alert is received or we see a really long fork (%s in cmd is replaced by message)"));
     strUsage +=HelpMessageOpt("-assumevalid=<hex>", strprintf(_("If this block is in the chain assume that it and its ancestors are valid and potentially skip their script verification (0 to verify all, default: %s, testnet: %s)"), defaultChainParams->GetConsensus().defaultAssumeValid.GetHex(), testnetChainParams->GetConsensus().defaultAssumeValid.GetHex()));
+    strUsage += HelpMessageOpt("-blocksdir=<dir>", _("Specify blocks directory (default: <datadir>/blocks)"));
     strUsage += HelpMessageOpt("-blocknotify=<cmd>", _("Execute command when the best block changes (%s in cmd is replaced by block hash)"));
     strUsage += HelpMessageOpt("-blockreconstructionextratxn=<n>", strprintf(_("Extra transactions to keep in memory for compact block reconstructions (default: %u)"), DEFAULT_BLOCK_RECONSTRUCTION_EXTRA_TXN));
     if (showDebug)
@@ -594,7 +595,7 @@ void CleanupBlockRevFiles()
     // Remove the rev files immediately and insert the blk file paths into an
     // ordered map keyed by block file index.
     LogPrintf("Removing unusable blk?????.dat and rev?????.dat files for -reindex with -prune\n");
-    fs::path blocksdir = GetDataDir() / "blocks";
+    fs::path blocksdir = GetBlocksDir();
     for (fs::directory_iterator it(blocksdir); it != fs::directory_iterator(); it++) {
         if (fs::is_regular_file(*it) &&
             it->path().filename().string().length() == 12 &&
@@ -897,6 +898,10 @@ bool AppInitParameterInteraction()
 
     // also see: InitParameterInteraction()
 
+    if (!fs::is_directory(GetBlocksDir(false))) {
+        return InitError(strprintf(_("Specified blocks directory \"%s\" does not exist.\n"), gArgs.GetArg("-blocksdir", "").c_str()));
+    }
+
     // if using block pruning, then disallow txindex
     if (gArgs.GetArg("-prune", 0)) {
         if (gArgs.GetBoolArg("-txindex", DEFAULT_TXINDEX))
@@ -1622,7 +1627,7 @@ bool AppInitMain()
 
     // ********************************************************* Step 10: import blocks
 
-    if (!CheckDiskSpace())
+    if (!CheckDiskSpace() && !CheckDiskSpace(0, true))
         return false;
 
     // Either install a handler to notify us when genesis activates, or set fHaveGenesis directly.