From f3fbfdaa379ac9df19b17da2f214dbaef910d865 Mon Sep 17 00:00:00 2001
From: Tomasz Grabiec <tgrabiec@scylladb.com>
Date: Fri, 24 Mar 2023 17:00:27 +0100
Subject: [PATCH] db: tablets: Add printers

Example:

TRACE 2023-03-30 12:06:33,918 [shard 0] tablets - Read tablet metadata: {
  8cd5b560-cee2-11ed-9cd5-7f37187f2167: {
    [0]: last_token=-6917529027641081857, replicas={4fe5c4d5-7030-4ddd-8117-ba22c29f4f57:0},
    [1]: last_token=-4611686018427387905, replicas={3160b965-1925-4677-884b-c761e2bf4272:0},
    [2]: last_token=-2305843009213693953, replicas={3160b965-1925-4677-884b-c761e2bf4272:0},
    [3]: last_token=-1, replicas={4fe5c4d5-7030-4ddd-8117-ba22c29f4f57:0},
    [4]: last_token=2305843009213693951, replicas={3160b965-1925-4677-884b-c761e2bf4272:0},
    [5]: last_token=4611686018427387903, replicas={4fe5c4d5-7030-4ddd-8117-ba22c29f4f57:0},
    [6]: last_token=6917529027641081855, replicas={4fe5c4d5-7030-4ddd-8117-ba22c29f4f57:0},
    [7]: last_token=9223372036854775807, replicas={3160b965-1925-4677-884b-c761e2bf4272:0}
  }
}
---
 locator/tablets.cc | 42 ++++++++++++++++++++++++++++++++++++++++++
 locator/tablets.hh |  3 +++
 2 files changed, 45 insertions(+)

diff --git a/locator/tablets.cc b/locator/tablets.cc
index baf0ba2851..021389ffcb 100644
--- a/locator/tablets.cc
+++ b/locator/tablets.cc
@@ -115,4 +115,46 @@ const tablet_transition_info* tablet_map::get_tablet_transition_info(tablet_id i
     return &i->second;
 }
 
+std::ostream& operator<<(std::ostream& out, tablet_id id) {
+    return out << size_t(id);
+}
+
+std::ostream& operator<<(std::ostream& out, const tablet_replica& r) {
+    return out << r.host << ":" << r.shard;
+}
+
+std::ostream& operator<<(std::ostream& out, const tablet_map& r) {
+    if (r.tablet_count() == 0) {
+        return out << "{}";
+    }
+    out << "{";
+    bool first = true;
+    tablet_id tid = r.first_tablet();
+    for (auto&& tablet : r._tablets) {
+        if (!first) {
+            out << ",";
+        }
+        out << format("\n    [{}]: last_token={}, replicas={}", tid, r.get_last_token(tid), tablet.replicas);
+        if (auto tr = r.get_tablet_transition_info(tid)) {
+            out << format(", new_replicas={}, pending={}", tr->next, tr->pending_replica);
+        }
+        first = false;
+        tid = *r.next_tablet(tid);
+    }
+    return out << "\n  }";
+}
+
+std::ostream& operator<<(std::ostream& out, const tablet_metadata& tm) {
+    out << "{";
+    bool first = true;
+    for (auto&& [id, map] : tm._tablets) {
+        if (!first) {
+            out << ",";
+        }
+        out << "\n  " << id << ": " << map;
+        first = false;
+    }
+    return out << "\n}";
+}
+
 }
diff --git a/locator/tablets.hh b/locator/tablets.hh
index 019909fbf6..84ff54b6f1 100644
--- a/locator/tablets.hh
+++ b/locator/tablets.hh
@@ -43,6 +43,7 @@ struct tablet_replica {
     bool operator==(const tablet_replica&) const = default;
 };
 
+std::ostream& operator<<(std::ostream&, tablet_id);
 std::ostream& operator<<(std::ostream&, const tablet_replica&);
 
 using tablet_replica_set = utils::small_vector<tablet_replica, 3>;
@@ -175,6 +176,7 @@ public:
     // Destroys gently.
     // The tablet map is not usable after this call and should be destroyed.
     future<> clear_gently();
+    friend std::ostream& operator<<(std::ostream&, const tablet_map&);
 private:
     void check_tablet_id(tablet_id) const;
 };
@@ -209,6 +211,7 @@ public:
     future<> clear_gently();
 public:
     bool operator==(const tablet_metadata&) const = default;
+    friend std::ostream& operator<<(std::ostream&, const tablet_metadata&);
 };
 
 }