wdb: calculate pagination count indexes per wallet instead of per block.

lib/wallet/txdb.js

@@ -383,10 +383,25 @@ class TXDB {
     return BlockRecord.decode(data);
   }
 
+  /**
+   * Get block hashes size.
+   * @param {Number} height
+   * @returns {Promise<Number>}
+   */
+
+  async getBlockTXsSize(height) {
+    const data = await this.bucket.get(layout.b.encode(height));
+
+    if (!data)
+      return 0;
+
+    return data.readUInt32LE(40, true);
+  }
+
   /**
    * Append to the global block record.
    * @param {Batch} b
-   * @param {Hash} hash
+   * @param {Hash} hash - transaction hash.
    * @param {BlockMeta} block
    * @returns {Promise}
    */
@@ -870,6 +885,9 @@ class TXDB {
       if (!block)
         return null;
 
+      // Get txIndex of the wallet.
+      extra.txIndex = await this.getBlockTXsSize(block.height);
+
       // Confirm transaction.
       return this.confirm(existing, block, extra);
     }
@@ -890,6 +908,9 @@ class TXDB {
       await this.removeDoubleOpen(tx);
     }
 
+    if (block)
+      extra.txIndex = await this.getBlockTXsSize(block.height);
+
     // Finally we can do a regular insertion.
     return this.insert(wtx, block, extra);
   }
@@ -1625,6 +1646,7 @@ class TXDB {
       /** @type {BlockExtraInfo} */
       const extra = {
         medianTime: mtp,
+        // txIndex is not used in revert.
         txIndex: i
       };
 

lib/wallet/walletdb.js

@@ -37,6 +37,7 @@ const {scanActions} = require('../blockchain/common');
 
 /** @typedef {import('../primitives/tx')} TX */
 /** @typedef {import('../blockchain/common').ScanAction} ScanAction */
+/** @typedef {import('../types').Hash} Hash */
 
 const {
   ChainState,
@@ -529,6 +530,7 @@ class WalletDB extends EventEmitter {
 
     const b = this.db.batch();
     const entries = await this.client.getEntries();
+    assert(entries, 'Could not get chain entries.');
 
     let tip = null;
 
@@ -2569,7 +2571,10 @@ class WalletDB extends EventEmitter {
         /** @type {BlockExtraInfo} */
         const extra = {
           medianTime: mtp,
-          txIndex: walletTXs.length
+          // txIndex will be recalculated in txdb. It will be local index
+          // to the wallet instead of the whole walletdb index.
+          // @see TXDB#add.
+          txIndex: 0
         };
 
         const txadded = await this._addTX(tx, tip, extra);