feat(multiplayer): lease allocating match claims

2026-09-11 00:14:00 +00:00 · 2026-09-01 10:36:13 +01:00
parent 03ff8e485e
commit 6f7d61eafb
6 changed files with 248 additions and 5 deletions
@@ -0,0 +1,134 @@
+package store
+
+import (
+	"context"
+	"database/sql"
+	"fmt"
+	"time"
+
+	"github.com/cosmic-clash/cosmic-clash/server/domain"
+)
+
+const AllocationClaimLease = time.Minute
+
+type PendingAllocation struct {
+	Request domain.AllocationRequest
+}
+
+const ClaimAllocatingMatchSQL = `WITH candidate AS (
+    SELECT match_id FROM matches
+    WHERE state = 'ALLOCATING' AND server_id IS NULL
+      AND (allocation_id IS NULL OR allocation_claimed_at <= $1)
+    ORDER BY created_at, match_id
+    LIMIT 1
+    FOR UPDATE SKIP LOCKED
+)
+UPDATE matches m
+SET allocation_id = 'allocation-' || candidate.match_id, allocation_claimed_at = $2
+FROM candidate
+WHERE m.match_id = candidate.match_id
+RETURNING m.match_id, m.region, m.protocol_version, m.allocation_id`
+
+const AllocatingMatchBuildSQL = `SELECT client_build
+FROM queue_tickets q
+JOIN match_participants mp ON mp.ticket_id = q.ticket_id AND mp.player_id = q.player_id
+WHERE mp.match_id = $1
+ORDER BY q.client_build`
+
+const BindAllocatedMatchSQL = `UPDATE matches
+SET server_id = $3
+WHERE match_id = $1 AND state = 'ALLOCATING' AND allocation_id = $2 AND server_id IS NULL
+  AND EXISTS (
+      SELECT 1 FROM allocations
+      WHERE allocation_id = $2 AND match_id = $1 AND server_id = $3 AND state = 'ALLOCATED'
+  )`
+
+const ReleaseAllocatedMatchClaimSQL = `UPDATE matches
+SET allocation_id = NULL, allocation_claimed_at = NULL
+WHERE match_id = $1 AND state = 'ALLOCATING' AND allocation_id = $2 AND server_id IS NULL`
+
+// ClaimAllocatingMatch returns one durable provider work item. The fixed
+// allocation ID is retained across a lease recovery, allowing every later
+// reconciliation step to reject a different server for the same match.
+func ClaimAllocatingMatch(ctx context.Context, db *sql.DB, transport string, now time.Time) (PendingAllocation, bool, error) {
+	if db == nil || (transport != "enet" && transport != "steam_sdr") || now.IsZero() {
+		return PendingAllocation{}, false, fmt.Errorf("invalid allocation claim arguments")
+	}
+	var item PendingAllocation
+	found := false
+	err := RunSerializable(ctx, db, DefaultSerializableAttempts, func(ctx context.Context, tx *sql.Tx) error {
+		var matchID, region string
+		var protocol int
+		var claimedID string
+		err := tx.QueryRowContext(ctx, ClaimAllocatingMatchSQL, now.Add(-AllocationClaimLease), now).Scan(&matchID, &region, &protocol, &claimedID)
+		if err == sql.ErrNoRows {
+			return nil
+		}
+		if err != nil {
+			return err
+		}
+		rows, err := tx.QueryContext(ctx, AllocatingMatchBuildSQL, matchID)
+		if err != nil {
+			return err
+		}
+		defer rows.Close()
+		build := ""
+		for rows.Next() {
+			var candidate string
+			if err := rows.Scan(&candidate); err != nil {
+				return err
+			}
+			if build == "" {
+				build = candidate
+			} else if build != candidate {
+				return fmt.Errorf("allocating match has mixed client builds")
+			}
+		}
+		if err := rows.Err(); err != nil {
+			return err
+		}
+		if build == "" {
+			return fmt.Errorf("allocating match has no participants")
+		}
+		item.Request = domain.AllocationRequest{AllocationID: claimedID, MatchID: matchID, Region: region, Build: build, Protocol: protocol, Transport: transport}
+		found = true
+		return nil
+	})
+	return item, found, err
+}
+
+func BindAllocatedMatch(ctx context.Context, db *sql.DB, allocation domain.Allocation) error {
+	if db == nil || allocation.MatchID == "" || allocation.AllocationID == "" || allocation.ServerID == "" || allocation.State != domain.ServerAllocated {
+		return fmt.Errorf("invalid allocated match binding")
+	}
+	result, err := db.ExecContext(ctx, BindAllocatedMatchSQL, allocation.MatchID, allocation.AllocationID, allocation.ServerID)
+	if err != nil {
+		return err
+	}
+	changed, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if changed != 1 {
+		return domain.ErrConflict
+	}
+	return nil
+}
+
+func ReleaseAllocatedMatchClaim(ctx context.Context, db *sql.DB, matchID, allocationID string) error {
+	if db == nil || matchID == "" || allocationID == "" {
+		return fmt.Errorf("invalid allocated match claim release")
+	}
+	result, err := db.ExecContext(ctx, ReleaseAllocatedMatchClaimSQL, matchID, allocationID)
+	if err != nil {
+		return err
+	}
+	changed, err := result.RowsAffected()
+	if err != nil {
+		return err
+	}
+	if changed != 1 {
+		return domain.ErrConflict
+	}
+	return nil
+}