113402286edoc: add txospenderindex release note (Lőrinc)ce06878288index: shrink txospenderindex value markers (Lőrinc) Pull request description: **Problem:** `TxoSpenderIndex` values are never read: `FindSpender()` only uses the key, which already encodes the spender's disk position, but the values are written as single-byte `\0`(instead of empty values). **Fix:** Write zero-byte markers for new `txospenderindex` entries instead. Existing indexes stay readable because both formats use the same keys and the value is ignored. Rebuilding is only needed to shrink old entries. **Related work:** This complements #35568, which saves another ~4.5 GB by dropping bloom filters. A #35531-style rewrite could let existing indexes reclaim both savings without a full rebuild. **Reproducer:** Automated tests weren't added, but the manual reproducer below builds both commits, checks old/new format compatibility through `gettxspendingprevout`, and prints rebuilt index sizes. On my mainnet datadir this PR shrank `txospenderindex` by ~3.4 GB (from 89G to 86G). <details><summary>Script + sample output</summary> ```bash BEFORE="89b4000ae06c72c5a14ee05ad70d3aece3f1b382" AFTER="1be799ef858c33158a302857b084e169b5bf8c1f" DATA_DIR="/mnt/my_storage/BitcoinData" LOG="${DATA_DIR}/debug.log" OUT='[{"txid":"0437cd7f8525ceed2324359c2d0ba26006d92d856a9c20fa0241106ee5a597c9","vout":0}]' SPEND="f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16"; \ for b in before after; do [ -x ./build-$b/bin/bitcoin-cli ] && ./build-$b/bin/bitcoin-cli -datadir="${DATA_DIR}" stop >/dev/null 2>&1 || true; done; sleep 10; \ git reset --hard >/dev/null 2>&1 && git clean -fxd >/dev/null 2>&1 && (git fetch origin "$BEFORE" "$AFTER" >/dev/null 2>&1 || true) && \ for c in before:$BEFORE after:$AFTER; do git checkout ${c#*:} >/dev/null 2>&1 && cmake -B build-${c%:*} -DCMAKE_BUILD_TYPE=Release >/dev/null 2>&1 && cmake --build build-${c%:*} -j --target bitcoind bitcoin-cli >/dev/null 2>&1; done && \ for b in before after; do ./build-$b/bin/bitcoin-cli -datadir="${DATA_DIR}" stop >/dev/null 2>&1 || true; done; sleep 10; \ start_node() { [ "$2" = wipe ] && rm -rf "${DATA_DIR}/indexes/txospenderindex" "${LOG}"; : > "${LOG}"; ./build-"$1"/bin/bitcoind -datadir="${DATA_DIR}" -txospenderindex=1 -connect=0 -printtoconsole=0 & pid=$!; while ! grep -Fq 'txospenderindex is enabled at height' "${LOG}" 2>/dev/null; do kill -0 "$pid" 2>/dev/null || { tail -100 "${LOG}"; return 1; }; sleep 5; done; }; \ check_spend() { result="$(./build-"$1"/bin/bitcoin-cli -datadir="${DATA_DIR}" gettxspendingprevout "$OUT" '{"mempool_only":false}')"; echo "$2: $result"; echo "$result" | grep -q "$SPEND"; }; \ stop_node() { ./build-"$1"/bin/bitcoin-cli -datadir="${DATA_DIR}" stop >/dev/null; wait "$pid"; }; \ echo "prevout: 0437cd7f8525ceed2324359c2d0ba26006d92d856a9c20fa0241106ee5a597c9:0 -> ${SPEND}" && \ start_node before wipe && check_spend before "old binary reads old-format index" && du -sh "${DATA_DIR}/indexes/txospenderindex"; stop_node before && \ start_node after && check_spend after "new binary reads old-format index"; stop_node after && \ start_node after wipe && check_spend after "new binary reads new-format index" && du -sh "${DATA_DIR}/indexes/txospenderindex"; stop_node after && \ start_node before && check_spend before "old binary reads new-format index"; stop_node before ``` Expected result, trimmed to the relevant compatibility and size lines: ```text prevout: 0437cd7f8525ceed2324359c2d0ba26006d92d856a9c20fa0241106ee5a597c9:0 -> f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16 old binary reads old-format index: [ ... "spendingtxid": "f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16" ... ] 89G /mnt/my_storage/BitcoinData/indexes/txospenderindex new binary reads old-format index: [ ... "spendingtxid": "f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16" ... ] new binary reads new-format index: [ ... "spendingtxid": "f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16" ... ] 86G /mnt/my_storage/BitcoinData/indexes/txospenderindex old binary reads new-format index: [ ... "spendingtxid": "f4184fc596403b9d638783cf57adfe4c75c605f6356fbc91338530e9831e9e16" ... ] ``` </details> ACKs for top commit: davidgumberg: crACK113402286esedited: ACK113402286eekzyis: utACK113402286eandrewtoth: ACK113402286eTree-SHA512: 07945b9470670115e27a1ef51e64164da7b91e550fdcb59952bfc98d862264b405e8fd8c3267c42718a39823f853057390d031d936d6e0b2172ec07e36cfdd67
Bitcoin Core
Setup
Bitcoin Core is the original Bitcoin client and it builds the backbone of the network. It downloads and, by default, stores the entire history of Bitcoin transactions, which requires several hundred gigabytes or more of disk space. Depending on the speed of your computer and network connection, the synchronization process can take anywhere from a few hours to several days or more.
To download Bitcoin Core, visit bitcoincore.org.
Running
The following are some helpful notes on how to run Bitcoin Core on your native platform.
Unix
Unpack the files into a directory and run:
bin/bitcoin-qt(GUI) orbin/bitcoind(headless)bin/bitcoin(wrapper command)
The bitcoin command supports subcommands like bitcoin gui, bitcoin node, and bitcoin rpc exposing different functionality. Subcommands can be listed with bitcoin help.
Windows
Unpack the files into a directory, and then run bitcoin-qt.exe.
macOS
Drag Bitcoin Core to your applications folder, and then run Bitcoin Core.
Need Help?
- See the documentation at the Bitcoin Wiki for help and more information.
- Ask for help on Bitcoin StackExchange.
- Ask for help on #bitcoin on Libera Chat. If you don't have an IRC client, you can use web.libera.chat.
- Ask for help on the BitcoinTalk forums, in the Technical Support board.
Building
The following are developer notes on how to build Bitcoin Core on your native platform. They are not complete guides, but include notes on the necessary libraries, compile flags, etc.
- Dependencies
- macOS Build Notes
- Unix Build Notes
- Windows Build Notes
- FreeBSD Build Notes
- OpenBSD Build Notes
- NetBSD Build Notes
Development
The Bitcoin repo's root README contains relevant information on the development process and automated testing.
- Developer Notes
- Productivity Notes
- Release Process
- Source Code Documentation (External Link)
- Translation Process
- Translation Strings Policy
- JSON-RPC Interface
- Unauthenticated REST Interface
- BIPS
- Dnsseed Policy
- Benchmarking
- Internal Design Docs
Resources
- Discuss on the BitcoinTalk forums, in the Development & Technical Discussion board.
- Discuss project-specific development on #bitcoin-core-dev on Libera Chat. If you don't have an IRC client, you can use web.libera.chat.
Miscellaneous
- Assets Attribution
- bitcoin.conf Configuration File
- CJDNS Support
- Files
- Fuzz-testing
- I2P Support
- Init Scripts (systemd/upstart/openrc)
- Managing Wallets
- Multisig Tutorial
- Offline Signing Tutorial
- P2P bad ports definition and list
- PSBT support
- Reduce Memory
- Reduce Traffic
- Tor Support
- Transaction Relay Policy
- ZMQ
License
Distributed under the MIT software license.