From 4f9f7468ee55c3f580eee4923225f08db0db08cf Mon Sep 17 00:00:00 2001
From: Doug Hoyte <doug@hcsw.org>
Date: Thu, 5 Sep 2024 15:26:57 -0400
Subject: [PATCH] use const refs for std::function callbacks

---
 src/ActiveMonitors.h | 12 ++++++------
 src/DBQuery.h        |  6 +++---
 src/ThreadPool.h     |  4 ++--
 3 files changed, 11 insertions(+), 11 deletions(-)

diff --git a/src/ActiveMonitors.h b/src/ActiveMonitors.h
index dbc8c66..633728a 100644
--- a/src/ActiveMonitors.h
+++ b/src/ActiveMonitors.h
@@ -85,7 +85,7 @@ struct ActiveMonitors : NonCopyable {
         conns.erase(connId);
     }
 
-    void process(lmdb::txn &txn, defaultDb::environment::View_Event &ev, std::function<void(RecipientList &&, uint64_t)> cb) {
+    void process(lmdb::txn &txn, defaultDb::environment::View_Event &ev, const std::function<void(RecipientList &&, uint64_t)> &cb) {
         RecipientList recipients;
 
         auto processMonitorSet = [&](MonitorSet &ms){
@@ -101,7 +101,7 @@ struct ActiveMonitors : NonCopyable {
             }
         };
 
-        auto processMonitorsExact = [&]<typename T>(btree_map<T, MonitorSet> &m, const T &key, std::function<bool(const T &)> matches){
+        auto processMonitorsExact = [&]<typename T>(btree_map<T, MonitorSet> &m, const T &key, const std::function<bool(const T &)> &matches){
             auto it = m.upper_bound(key);
 
             if (it == m.begin()) return;
@@ -118,21 +118,21 @@ struct ActiveMonitors : NonCopyable {
 
         {
             Bytes32 id(packed.id());
-            processMonitorsExact(allIds, id, static_cast<std::function<bool(const Bytes32&)>>([&](const Bytes32 &val){
+            processMonitorsExact(allIds, id, static_cast<const std::function<bool(const Bytes32&)> &>([&](const Bytes32 &val){
                 return id == val;
             }));
         }
 
         {
             Bytes32 pubkey(packed.pubkey());
-            processMonitorsExact(allAuthors, pubkey, static_cast<std::function<bool(const Bytes32&)>>([&](const Bytes32 &val){
+            processMonitorsExact(allAuthors, pubkey, static_cast<const std::function<bool(const Bytes32&)> &>([&](const Bytes32 &val){
                 return pubkey == val;
             }));
         }
 
         packed.foreachTag([&](char tagName, std::string_view tagVal){
             auto &tagSpec = getTagSpec(tagName, tagVal);
-            processMonitorsExact(allTags, tagSpec, static_cast<std::function<bool(const std::string&)>>([&](const std::string &val){
+            processMonitorsExact(allTags, tagSpec, static_cast<const std::function<bool(const std::string&)> &>([&](const std::string &val){
                 return tagSpec == val;
             }));
             return true;
@@ -140,7 +140,7 @@ struct ActiveMonitors : NonCopyable {
 
         {
             auto kind = packed.kind();
-            processMonitorsExact(allKinds, kind, static_cast<std::function<bool(const uint64_t&)>>([&](const uint64_t &val){
+            processMonitorsExact(allKinds, kind, static_cast<const std::function<bool(const uint64_t&)> &>([&](const uint64_t &val){
                 return kind == val;
             }));
         }
diff --git a/src/DBQuery.h b/src/DBQuery.h
index 6749982..7e91f4b 100644
--- a/src/DBQuery.h
+++ b/src/DBQuery.h
@@ -226,7 +226,7 @@ struct DBScan : NonCopyable {
         refillScanDepth = 10 * initialScanDepth;
     }
 
-    bool scan(lmdb::txn &txn, std::function<bool(uint64_t)> handleEvent, std::function<bool(uint64_t)> doPause) {
+    bool scan(lmdb::txn &txn, const std::function<bool(uint64_t)> &handleEvent, const std::function<bool(uint64_t)> &doPause) {
         auto cmp = [](auto &a, auto &b){
             return a.created() == b.created() ? a.levId() > b.levId() : a.created() > b.created();
         };
@@ -299,7 +299,7 @@ struct DBQuery : NonCopyable {
     DBQuery(const tao::json::value &filter, uint64_t maxLimit = MAX_U64) : sub(Subscription(1, ".", NostrFilterGroup::unwrapped(filter, maxLimit))) {}
 
     // If scan is complete, returns true
-    bool process(lmdb::txn &txn, std::function<void(const Subscription &, uint64_t)> cb, uint64_t timeBudgetMicroseconds = MAX_U64, bool logMetrics = false) {
+    bool process(lmdb::txn &txn, const std::function<void(const Subscription &, uint64_t)> &cb, uint64_t timeBudgetMicroseconds = MAX_U64, bool logMetrics = false) {
         while (filterGroupIndex < sub.filterGroup.size()) {
             const auto &f = sub.filterGroup.filters[filterGroupIndex];
 
@@ -370,7 +370,7 @@ struct DBQuery : NonCopyable {
 };
 
 
-inline void foreachByFilter(lmdb::txn &txn, const tao::json::value &filter, std::function<void(uint64_t)> cb) {
+inline void foreachByFilter(lmdb::txn &txn, const tao::json::value &filter, const std::function<void(uint64_t)> &cb) {
     DBQuery query(filter);
 
     query.process(txn, [&](const auto &, uint64_t levId){
diff --git a/src/ThreadPool.h b/src/ThreadPool.h
index 573ce92..cb1fbe5 100644
--- a/src/ThreadPool.h
+++ b/src/ThreadPool.h
@@ -19,7 +19,7 @@ struct ThreadPool {
         join();
     }
 
-    void init(std::string name, uint64_t numThreads_, std::function<void(Thread &t)> cb) {
+    void init(std::string name, uint64_t numThreads_, const std::function<void(Thread &t)> &cb) {
         if (numThreads_ == 0) throw herr("must have more than 0 threads");
 
         numThreads = numThreads_;
@@ -49,7 +49,7 @@ struct ThreadPool {
         pool[who].inbox.push_move_all(m);
     }
 
-    void dispatchToAll(std::function<M()> cb) {
+    void dispatchToAll(const std::function<M()> &cb) {
         for (size_t i = 0; i < numThreads; i++) pool[i].inbox.push_move(cb());
     }