[addrman] Move CAddrMan::Unserialize to cpp file

Reviewer hint: use `git diff --color-moved=dimmed-zebra
--color-moved-ws=ignore-all-space`

Co-authored-by: Amiti Uttarwar <amiti@uttarwar.org>

1 files changed, 171 insertions, 0 deletions

diff --git a/src/addrman.cpp b/src/addrman.cpp
index 58feb39b1b..ed5fd06288 100644
--- a/src/addrman.cpp
+++ b/src/addrman.cpp
@@ -197,10 +197,181 @@ void CAddrMan::Serialize(Stream& s_) const
     s << asmap_checksum;
 }
 
+template <typename Stream>
+void CAddrMan::Unserialize(Stream& s_)
+{
+    LOCK(cs);
+
+    assert(vRandom.empty());
+
+    Format format;
+    s_ >> Using<CustomUintFormatter<1>>(format);
+
+    int stream_version = s_.GetVersion();
+    if (format >= Format::V3_BIP155) {
+        // Add ADDRV2_FORMAT to the version so that the CNetAddr and CAddress
+        // unserialize methods know that an address in addrv2 format is coming.
+        stream_version |= ADDRV2_FORMAT;
+    }
+
+    OverrideStream<Stream> s(&s_, s_.GetType(), stream_version);
+
+    uint8_t compat;
+    s >> compat;
+    const uint8_t lowest_compatible = compat - INCOMPATIBILITY_BASE;
+    if (lowest_compatible > FILE_FORMAT) {
+        throw std::ios_base::failure(strprintf(
+                    "Unsupported format of addrman database: %u. It is compatible with formats >=%u, "
+                    "but the maximum supported by this version of %s is %u.",
+                    format, lowest_compatible, PACKAGE_NAME, static_cast<uint8_t>(FILE_FORMAT)));
+    }
+
+    s >> nKey;
+    s >> nNew;
+    s >> nTried;
+    int nUBuckets = 0;
+    s >> nUBuckets;
+    if (format >= Format::V1_DETERMINISTIC) {
+        nUBuckets ^= (1 << 30);
+    }
+
+    if (nNew > ADDRMAN_NEW_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE || nNew < 0) {
+        throw std::ios_base::failure(
+                strprintf("Corrupt CAddrMan serialization: nNew=%d, should be in [0, %u]",
+                    nNew,
+                    ADDRMAN_NEW_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE));
+    }
+
+    if (nTried > ADDRMAN_TRIED_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE || nTried < 0) {
+        throw std::ios_base::failure(
+                strprintf("Corrupt CAddrMan serialization: nTried=%d, should be in [0, %u]",
+                    nTried,
+                    ADDRMAN_TRIED_BUCKET_COUNT * ADDRMAN_BUCKET_SIZE));
+    }
+
+    // Deserialize entries from the new table.
+    for (int n = 0; n < nNew; n++) {
+        CAddrInfo &info = mapInfo[n];
+        s >> info;
+        mapAddr[info] = n;
+        info.nRandomPos = vRandom.size();
+        vRandom.push_back(n);
+    }
+    nIdCount = nNew;
+
+    // Deserialize entries from the tried table.
+    int nLost = 0;
+    for (int n = 0; n < nTried; n++) {
+        CAddrInfo info;
+        s >> info;
+        int nKBucket = info.GetTriedBucket(nKey, m_asmap);
+        int nKBucketPos = info.GetBucketPosition(nKey, false, nKBucket);
+        if (info.IsValid()
+                && vvTried[nKBucket][nKBucketPos] == -1) {
+            info.nRandomPos = vRandom.size();
+            info.fInTried = true;
+            vRandom.push_back(nIdCount);
+            mapInfo[nIdCount] = info;
+            mapAddr[info] = nIdCount;
+            vvTried[nKBucket][nKBucketPos] = nIdCount;
+            nIdCount++;
+        } else {
+            nLost++;
+        }
+    }
+    nTried -= nLost;
+
+    // Store positions in the new table buckets to apply later (if possible).
+    // An entry may appear in up to ADDRMAN_NEW_BUCKETS_PER_ADDRESS buckets,
+    // so we store all bucket-entry_index pairs to iterate through later.
+    std::vector<std::pair<int, int>> bucket_entries;
+
+    for (int bucket = 0; bucket < nUBuckets; ++bucket) {
+        int num_entries{0};
+        s >> num_entries;
+        for (int n = 0; n < num_entries; ++n) {
+            int entry_index{0};
+            s >> entry_index;
+            if (entry_index >= 0 && entry_index < nNew) {
+                bucket_entries.emplace_back(bucket, entry_index);
+            }
+        }
+    }
+
+    // If the bucket count and asmap checksum haven't changed, then attempt
+    // to restore the entries to the buckets/positions they were in before
+    // serialization.
+    uint256 supplied_asmap_checksum;
+    if (m_asmap.size() != 0) {
+        supplied_asmap_checksum = SerializeHash(m_asmap);
+    }
+    uint256 serialized_asmap_checksum;
+    if (format >= Format::V2_ASMAP) {
+        s >> serialized_asmap_checksum;
+    }
+    const bool restore_bucketing{nUBuckets == ADDRMAN_NEW_BUCKET_COUNT &&
+        serialized_asmap_checksum == supplied_asmap_checksum};
+
+    if (!restore_bucketing) {
+        LogPrint(BCLog::ADDRMAN, "Bucketing method was updated, re-bucketing addrman entries from disk\n");
+    }
+
+    for (auto bucket_entry : bucket_entries) {
+        int bucket{bucket_entry.first};
+        const int entry_index{bucket_entry.second};
+        CAddrInfo& info = mapInfo[entry_index];
+
+        // Don't store the entry in the new bucket if it's not a valid address for our addrman
+        if (!info.IsValid()) continue;
+
+        // The entry shouldn't appear in more than
+        // ADDRMAN_NEW_BUCKETS_PER_ADDRESS. If it has already, just skip
+        // this bucket_entry.
+        if (info.nRefCount >= ADDRMAN_NEW_BUCKETS_PER_ADDRESS) continue;
+
+        int bucket_position = info.GetBucketPosition(nKey, true, bucket);
+        if (restore_bucketing && vvNew[bucket][bucket_position] == -1) {
+            // Bucketing has not changed, using existing bucket positions for the new table
+            vvNew[bucket][bucket_position] = entry_index;
+            ++info.nRefCount;
+        } else {
+            // In case the new table data cannot be used (bucket count wrong or new asmap),
+            // try to give them a reference based on their primary source address.
+            bucket = info.GetNewBucket(nKey, m_asmap);
+            bucket_position = info.GetBucketPosition(nKey, true, bucket);
+            if (vvNew[bucket][bucket_position] == -1) {
+                vvNew[bucket][bucket_position] = entry_index;
+                ++info.nRefCount;
+            }
+        }
+    }
+
+    // Prune new entries with refcount 0 (as a result of collisions or invalid address).
+    int nLostUnk = 0;
+    for (auto it = mapInfo.cbegin(); it != mapInfo.cend(); ) {
+        if (it->second.fInTried == false && it->second.nRefCount == 0) {
+            const auto itCopy = it++;
+            Delete(itCopy->first);
+            ++nLostUnk;
+        } else {
+            ++it;
+        }
+    }
+    if (nLost + nLostUnk > 0) {
+        LogPrint(BCLog::ADDRMAN, "addrman lost %i new and %i tried addresses due to collisions or invalid addresses\n", nLostUnk, nLost);
+    }
+
+    Check();
+}
+
 // explicit instantiation
 template void CAddrMan::Serialize(CHashWriter& s) const;
 template void CAddrMan::Serialize(CAutoFile& s) const;
 template void CAddrMan::Serialize(CDataStream& s) const;
+template void CAddrMan::Unserialize(CAutoFile& s);
+template void CAddrMan::Unserialize(CHashVerifier<CAutoFile>& s);
+template void CAddrMan::Unserialize(CDataStream& s);
+template void CAddrMan::Unserialize(CHashVerifier<CDataStream>& s);
 
 CAddrInfo* CAddrMan::Find(const CNetAddr& addr, int* pnId)
 {