perf: optimize get_inference_history query and add indexes

Query optimization (dspy):
- Replace UNION ALL + sort with two parallel queries (asyncio.gather)
  that each use (userid, use_time) composite index
- Python-side merge-sort of two pre-sorted sequences O(n)
- Concurrent FileStorage reads for ioinfo (asyncio.gather)

Indexes (models/*.json + /tmp/llmage_history_indexes.sql):
- llmusage: add idx_llmusage_userid_usetime (userid, use_time)
- llmusage_history: add idx_lh_userid_usetime (userid, use_time)
  (was missing userid index entirely - main bottleneck)

models/llmusage.json

@@ -135,6 +135,14 @@
                 "accounting_status",
                 "use_date"
             ]
+        },
+        {
+            "name": "idx_llmusage_userid_usetime",
+            "idxtype": "index",
+            "idxfields": [
+                "userid",
+                "use_time"
+            ]
         }
     ]
 }

models/llmusage_history.json

@@ -136,6 +136,11 @@
             "name": "idx_lh_backup_time",
             "idxtype": "index",
             "idxfields": ["backup_time"]
+        },
+        {
+            "name": "idx_lh_userid_usetime",
+            "idxtype": "index",
+            "idxfields": ["userid", "use_time"]
         }
     ]
 }

wwwroot/api/get_inference_history.dspy

@@ -1,5 +1,6 @@
 #!/usr/bin/env python3
 import json
+import asyncio
 
 result = {'success': False, 'rows': [], 'total': 0, 'page': 1, 'page_size': 10}
 
@@ -22,63 +23,71 @@ try:
 
         where_clause = " and ".join(conditions)
 
-        # Count total from both tables
-        count_sql = f"""
-            select count(*) as cnt from (
-                select id from llmusage where {where_clause}
-                union all
-                select id from llmusage_history where {where_clause}
-            ) t
-        """
-        count_recs = await sor.sqlExe(count_sql, ns)
-        total = count_recs[0].cnt if count_recs else 0
+        # Count total from both tables (并行两个 count 查询)
+        count_sql = f"select count(*) as cnt from {{table}} where {where_clause}"
+        cnt1_recs, cnt2_recs = await asyncio.gather(
+            sor.sqlExe(count_sql.format(table='llmusage'), ns),
+            sor.sqlExe(count_sql.format(table='llmusage_history'), ns),
+        )
+        total = (cnt1_recs[0].cnt if cnt1_recs else 0) + (cnt2_recs[0].cnt if cnt2_recs else 0)
 
-        # UNION ALL query with pagination, time descending
+        # 优化点 1: 分别查询两张表, 让各自走 (userid, use_time) 复合索引
+        # 每表取前 offset+page_size 条 (已按 use_time desc 排好)
         offset = (page - 1) * page_size
-        query_sql = f"""
-            select id, llmid, use_date, use_time, userid, usages, ioinfo,
-                   status, taskid, amount, cost, userorgid, accounting_status
-            from (
-                select id, llmid, use_date, use_time, userid, usages, ioinfo,
-                       status, taskid, amount, cost, userorgid, accounting_status
-                from llmusage where {where_clause}
-                union all
-                select id, llmid, use_date, use_time, userid, usages, ioinfo,
-                       status, taskid, amount, cost, userorgid, accounting_status
-                from llmusage_history where {where_clause}
-            ) t
-            order by use_time desc
-            limit {page_size} offset {offset}
-        """
-        recs = await sor.sqlExe(query_sql, ns)
+        fetch = offset + page_size
+        select_cols = ("id, llmid, use_date, use_time, userid, usages, ioinfo, "
+                       "status, taskid, amount, cost, userorgid, accounting_status")
 
-        rows = []
-        for r in (recs or []):
-            row = dict(r)
-            # Read ioinfo content from FileStorage
+        q1 = f"select {select_cols} from llmusage where {where_clause} order by use_time desc limit {fetch}"
+        q2 = f"select {select_cols} from llmusage_history where {where_clause} order by use_time desc limit {fetch}"
+        recs1, recs2 = await asyncio.gather(
+            sor.sqlExe(q1, ns),
+            sor.sqlExe(q2, ns),
+        )
+
+        # 优化点 2: Python 归并两个已排序序列 (O(n) 比 SQL UNION+sort 快)
+        merged = []
+        i = j = 0
+        rows1 = [dict(r) for r in (recs1 or [])]
+        rows2 = [dict(r) for r in (recs2 or [])]
+        while i < len(rows1) and j < len(rows2):
+            if (rows1[i].get('use_time') or '') >= (rows2[j].get('use_time') or ''):
+                merged.append(rows1[i]); i += 1
+            else:
+                merged.append(rows2[j]); j += 1
+        merged.extend(rows1[i:])
+        merged.extend(rows2[j:])
+
+        # 应用分页
+        page_rows = merged[offset:offset + page_size]
+
+        # 优化点 3: 并发读取 ioinfo 文件 (不再串行 await)
+        import aiofiles
+        from ahserver.filestorage import FileStorage
+        fs = FileStorage()
+
+        async def _load_io(row):
             webpath = row.get('ioinfo')
             io_content = None
             if webpath:
                 try:
-                    from ahserver.filestorage import FileStorage
-                    fs = FileStorage()
                     real_path = fs.realPath(webpath)
-                    import aiofiles
                     async with aiofiles.open(real_path, 'rb') as f:
                         bin_data = await f.read()
                     io_content = json.loads(bin_data.decode('utf-8'))
                 except Exception:
                     io_content = None
             row['io_content'] = io_content
-            # Parse usages if it's a JSON string
             if isinstance(row.get('usages'), str):
                 try:
                     row['usages'] = json.loads(row['usages'])
                 except Exception:
                     pass
-            rows.append(row)
+            return row
 
-        result['rows'] = rows
+        rows = await asyncio.gather(*[_load_io(r) for r in page_rows])
+
+        result['rows'] = list(rows)
         result['total'] = total
         result['page'] = page
         result['page_size'] = page_size