add new mehods to MySqlDbWrapper (batch requests)

lib/db/mysql-db-wrapper.js

@@ -1358,6 +1358,26 @@ class MySqlDbWrapper {
     return (result.length == 0) ? null : result[0].txnID
   }
 
+  /**
+   * Get the mysql IDs of a collection of transactions
+   * @param {string[]} txids - txids of the transactions
+   * @returns {object[]} returns an array of {txnTxid: txnId}
+   */
+  async getTransactionsIds(txids) {
+    if (txids.length == 0)
+      return []
+
+    const sqlQuery = 'SELECT `txnID`, `txnTxid` FROM `transactions` WHERE `txnTxid` IN (?)'
+    const params = [txids]
+    const query = mysql.format(sqlQuery, params)
+    const results = await this._query(query)
+
+    const ret = {}
+    for (let r of results)
+      ret[r.txnTxid] = r.txnID
+    return ret
+  }
+
   /**
    * Get the mysql IDs of a set of transactions
    * @param {string[]} txid - array of transactions txids
@@ -1396,6 +1416,29 @@ class MySqlDbWrapper {
     return this._query(query)
   }
 
+  /**
+   * Insert a collection of transactions in db
+   * @param {object[]} txs - array of {txid, version, locktime}
+   */
+  async addTransactions(txs) {
+    if (txs.length == 0)
+      return
+
+    const sqlQuery = 'INSERT INTO `transactions` \
+      (txnTxid, txnCreated, txnVersion, txnLocktime) VALUES ? \
+      ON DUPLICATE KEY UPDATE txnVersion = VALUES(txnVersion)'
+
+    const params = [txs.map(tx => [
+      tx.txid,
+      tx.created,
+      tx.version,
+      tx.locktime
+    ])]
+
+    const query = mysql.format(sqlQuery, params)
+    return this._query(query)
+  }
+
   /**
    * Get a transaction for a given txid
    * @param {string} txid - txid of the transaction
@@ -1773,6 +1816,21 @@ class MySqlDbWrapper {
     return (result.length == 1) ? result[0] : null
   }
 
+  /**
+   * Get a collection of blocks identified by the blocks hashes
+   * @param {string[]} hashes - blocks hashes
+   * @returns {object[]} returns the blocks
+   */
+  async getBlocksByHashes(hashes) {
+    if (hashes.length == 0)
+      return []
+
+    const sqlQuery = 'SELECT * FROM `blocks` WHERE `blockHash` IN (?)'
+    const params = [hashes]
+    const query = mysql.format(sqlQuery, params)
+    return await this._query(query)
+  }
+
   /**
    * Get details about all blocks at a given block height
    * @param {integer} height - block height