Merge bitcoin/bitcoin#23491: scripted-diff: Move minisketchwrapper to src/node

faba1abe46 Sort file list after rename (MarcoFalke)
fa8f60e311 scripted-diff: Move minisketchwrapper to src/node (MarcoFalke)

Pull request description:

  The newly added wrapper is currently in the node library, but not placed in the node directory. While it is possible to use the wrapper outside of a node context (for example in a utility), it seems unlikely. Either way, I think the wrapper should either be moved to the util lib+dir or the node lib+dir, not something in-between.

  Also, fix incorrect comment `BITCOIN_DBWRAPPER_H`.

ACKs for top commit:
  fanquake:
    ACK faba1abe46. I saw the comment in #21515, however given there hasn't been any new activity there, I'm going to merge this now.

Tree-SHA512: fccc0cfd1fee661152a1378587b96795ffb7a7eceb6d2c27ea5401993fd8b9c0a92579fdba61203917ae6565269cb28d0973464fb6201dabf72a5143495d3e77

src/node/minisketchwrapper.cpp

@@ -0,0 +1,77 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#include <node/minisketchwrapper.h>
+
+#include <logging.h>
+#include <util/time.h>
+
+#include <minisketch.h>
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <optional>
+#include <utility>
+#include <vector>
+
+namespace {
+
+static constexpr uint32_t BITS = 32;
+
+uint32_t FindBestImplementation()
+{
+    std::optional<std::pair<int64_t, uint32_t>> best;
+
+    uint32_t max_impl = Minisketch::MaxImplementation();
+    for (uint32_t impl = 0; impl <= max_impl; ++impl) {
+        std::vector<int64_t> benches;
+        uint64_t offset = 0;
+        /* Run a little benchmark with capacity 32, adding 184 entries, and decoding 11 of them once. */
+        for (int b = 0; b < 11; ++b) {
+            if (!Minisketch::ImplementationSupported(BITS, impl)) break;
+            Minisketch sketch(BITS, impl, 32);
+            auto start = GetTimeMicros();
+            for (uint64_t e = 0; e < 100; ++e) {
+                sketch.Add(e*1337 + b*13337 + offset);
+            }
+            for (uint64_t e = 0; e < 84; ++e) {
+                sketch.Add(e*1337 + b*13337 + offset);
+            }
+            offset += (*sketch.Decode(32))[0];
+            auto stop = GetTimeMicros();
+            benches.push_back(stop - start);
+        }
+        /* Remember which implementation has the best median benchmark time. */
+        if (!benches.empty()) {
+            std::sort(benches.begin(), benches.end());
+            if (!best || best->first > benches[5]) {
+                best = std::make_pair(benches[5], impl);
+            }
+        }
+    }
+    assert(best.has_value());
+    LogPrintf("Using Minisketch implementation number %i\n", best->second);
+    return best->second;
+}
+
+uint32_t Minisketch32Implementation()
+{
+    // Fast compute-once idiom.
+    static uint32_t best = FindBestImplementation();
+    return best;
+}
+
+} // namespace
+
+
+Minisketch MakeMinisketch32(size_t capacity)
+{
+    return Minisketch(BITS, Minisketch32Implementation(), capacity);
+}
+
+Minisketch MakeMinisketch32FP(size_t max_elements, uint32_t fpbits)
+{
+    return Minisketch::CreateFP(BITS, Minisketch32Implementation(), max_elements, fpbits);
+}

src/node/minisketchwrapper.h

@@ -0,0 +1,18 @@
+// Copyright (c) 2021 The Bitcoin Core developers
+// Distributed under the MIT software license, see the accompanying
+// file COPYING or http://www.opensource.org/licenses/mit-license.php.
+
+#ifndef BITCOIN_NODE_MINISKETCHWRAPPER_H
+#define BITCOIN_NODE_MINISKETCHWRAPPER_H
+
+#include <minisketch.h>
+
+#include <cstddef>
+#include <cstdint>
+
+/** Wrapper around Minisketch::Minisketch(32, implementation, capacity). */
+Minisketch MakeMinisketch32(size_t capacity);
+/** Wrapper around Minisketch::CreateFP. */
+Minisketch MakeMinisketch32FP(size_t max_elements, uint32_t fpbits);
+
+#endif // BITCOIN_NODE_MINISKETCHWRAPPER_H