add import script for existing game logs

src/server/Db.ts

@@ -5,6 +5,10 @@ import { logger } from '../common/Util'
 
 const log = logger('Db.ts')
 
+// assume 32766 SQLITE_MAX_VARIABLE_NUMBER
+// @see https://sqlite.org/limits.html
+const SQLITE_MAX_VARIABLE_NUMBER = 32766
+
 /**
  * TODO: create a more specific type for OrderBy.
  * It looks like this (example):
@@ -186,6 +190,9 @@ class Db {
     return this.get(table, check)[idcol] // get id manually
   }
 
+  /**
+   * Inserts data into table and returns the last insert id
+   */
   insert (table: string, data: Data): Integer.IntLike {
     const keys = Object.keys(data)
     const values = keys.map(k => data[k])
@@ -195,6 +202,45 @@ class Db {
     return this.run(sql, values).lastInsertRowid
   }
 
+  /**
+   * Inserts multiple datas into table. Returns the total number
+   * of changes.
+   */
+  insertMany (table: string, datas: Data[]): number {
+    if (datas.length === 0) {
+      return 0
+    }
+
+    const keys = Object.keys(datas[0])
+
+    const runChunk = (vars: string[], values: any[]) => {
+      const sql = `INSERT INTO ${table}
+        (${keys.join(',')})
+        VALUES ${vars.join(',')}`
+      return this.run(sql, values).changes
+    }
+
+    let len: number = 0
+    let vars: string[] = []
+    let values: any[] = []
+    let changes = 0
+    for (const data of datas) {
+      if (len + keys.length > SQLITE_MAX_VARIABLE_NUMBER) {
+        changes += runChunk(vars, values)
+        len = 0
+        vars = []
+        values = []
+      }
+      len += keys.length
+      vars.push('(' + keys.map(_ => '?').join(',') + ')')
+      values.push(...keys.map(k => data[k]))
+    }
+    if (len > 0) {
+      changes += runChunk(vars, values)
+    }
+    return changes
+  }
+
   update (table: string, data: Data, whereRaw: WhereRaw = {}): void {
     const keys = Object.keys(data)
     if (keys.length === 0) {