logs: show reindex progress in `ImportBlocks`
What the developer wrote
Authored by Lőrinc
logs: show reindex progress in `ImportBlocks`
### Summary
When triggering a reindex, users had no indication of how many files remained or how far along the process was.
### Fix
This patch prefetches the target file block file count to be able to show progress information.
Instead of just displaying which block file is being processed, it now indicates how many files remain.
### Reproducer + expected results
Running
```bash
cmake -B build && make -C build -DCMAKE_BUILD_TYPE=Release && ./build/bin/bitcoind -datadir=demo -reindex
```
Shows the block files one-by-one currently, there's no way to see how much work is left:
```
Reindexing block file blk00000.dat...
Loaded 119920 blocks from external file in 1228ms
Reindexing block file blk00001.dat...
Loaded 10671 blocks from external file in 284ms
Reindexing block file blk00002.dat...
Loaded 5459 blocks from external file in 263ms
Reindexing block file blk00003.dat...
Loaded 5595 blocks from external file in 267ms
```
After the change:
```
Reindexing block file blk00000.dat (0% complete)...
Loaded 119920 blocks from external file in 1255ms
Reindexing block file blk00001.dat (1% complete)...
Loaded 10671 blocks from external file in 303ms
Reindexing block file blk00002.dat (2% complete)...
Loaded 5459 blocks from external file in 278ms
Reindexing block file blk00003.dat (3% complete)...
Loaded 5595 blocks from external file in 285ms
```
What changed, and why it matters
This commit is a user-experience improvement, not a security fix. It adds a percentage-complete indicator to the log message shown while Bitcoin Core reindexes old block files. Before, users only saw which file was being processed; now they can see roughly how many files remain. There is no change to security-sensitive logic.
No security action required. Treat as a normal logging/UX improvement.
Security signals we found
No strong security signals were identified.
Evidence from the diff
The change refactors the reindex loop in src/node/blockstorage.cpp::ImportBlocks. It first counts how many blk*.dat files exist, then iterates through them with a for loop instead of an unbounded while(true), and adds a progress percentage to the LogInfo output. The filesystem checks, file opening, and block-loading calls remain functionally identical. No input validation, cryptography, consensus, networking, or privilege logic is modified.
Changed components
src/node/blockstorage.cpp::ImportBlocksInspect captured patch +8 / −7
diff --git a/src/node/blockstorage.cpp b/src/node/blockstorage.cpp
index 3c01ff2e..1163feb3 100644
--- a/src/node/blockstorage.cpp
+++ b/src/node/blockstorage.cpp
@@ -1220,26 +1220,27 @@ void ImportBlocks(ChainstateManager& chainman, std::span<const fs::path> import_
// -reindex
if (!chainman.m_blockman.m_blockfiles_indexed) {
- int nFile = 0;
+ int total_files{0};
+ while (fs::exists(chainman.m_blockman.GetBlockPosFilename(FlatFilePos(total_files, 0)))) {
+ total_files++;
+ }
+
// Map of disk positions for blocks with unknown parent (only used for reindex);
// parent hash -> child disk position, multiple children can have the same parent.
std::multimap<uint256, FlatFilePos> blocks_with_unknown_parent;
- while (true) {
+
+ for (int nFile{0}; nFile < total_files; ++nFile) {
FlatFilePos pos(nFile, 0);
- if (!fs::exists(chainman.m_blockman.GetBlockPosFilename(pos))) {
- break; // No block files left to reindex
- }
AutoFile file{chainman.m_blockman.OpenBlockFile(pos, /*fReadOnly=*/true)};
if (file.IsNull()) {
break; // This error is logged in OpenBlockFile
}
- LogInfo("Reindexing block file blk%05u.dat...", (unsigned int)nFile);
+ LogInfo("Reindexing block file blk%05u.dat (%d%% complete)...", (unsigned int)nFile, nFile * 100 / total_files);
chainman.LoadExternalBlockFile(file, &pos, &blocks_with_unknown_parent);
if (chainman.m_interrupt) {
LogInfo("Interrupt requested. Exit reindexing.");
return;
}
- nFile++;
}
WITH_LOCK(::cs_main, chainman.m_blockman.m_block_tree_db->WriteReindexing(false));
chainman.m_blockman.m_blockfiles_indexed = true;
Why this scored 15/100
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