From bc408ec6804ff16dc4c5c9cf155a5d47f4a55573 Mon Sep 17 00:00:00 2001
From: prathamesh0 <prathamesh.musale0@gmail.com>
Date: Tue, 13 Dec 2022 14:42:05 +0530
Subject: [PATCH] Fix the helper function to create a slice of required paths

---
 pkg/eth/helpers.go        | 39 +++++++++++++++++++++++++--------------
 pkg/eth/ipld_retriever.go | 19 +++++++++++++++----
 2 files changed, 40 insertions(+), 18 deletions(-)

diff --git a/pkg/eth/helpers.go b/pkg/eth/helpers.go
index 31783bb6..498b6ae6 100644
--- a/pkg/eth/helpers.go
+++ b/pkg/eth/helpers.go
@@ -74,26 +74,37 @@ func getPaths(path string, depth int) ([]byte, [][]byte, [][]byte, error) {
 	return headPath, stemPaths, slicePaths, nil
 }
 
-// iterative function to generate the set of slice paths
+// An iterative function to generate the set of slice paths
 func makeSlicePaths(path []byte, depth int, slicePaths *[][]byte) {
-	depth--                          // decrement the depth
-	nextPaths := make([][]byte, 16)  // slice to hold the next 16 paths
-	for i, step := range pathSteps { // iterate through steps
-		nextPath := append(path, step) // create next paths by adding steps to current path
-		nextPaths[i] = nextPath
-		newSlicePaths := append(*slicePaths, nextPath) // add next paths to the collection of all slice paths
-		slicePaths = &newSlicePaths
-	}
-
-	if depth == 0 { // if depth has reach 0, return
+	// return if depth has reached 0
+	if depth <= 0 {
 		return
 	}
-	for _, nextPath := range nextPaths { // if not, then we iterate over the next paths
-		makeSlicePaths(nextPath, depth, slicePaths) // and repeat the process for each one
+	depth--
+
+	// slice to hold the next 16 paths
+	nextPaths := make([][]byte, 0, 16)
+	for _, step := range pathSteps {
+		// create next paths by adding steps to current path
+		nextPath := make([]byte, len(path))
+		copy(nextPath, path)
+		nextPath = append(nextPath, step)
+
+		nextPaths = append(nextPaths, nextPath)
+
+		// also add the next path to the collection of all slice paths
+		dst := make([]byte, len(nextPath))
+		copy(dst, nextPath)
+		*slicePaths = append(*slicePaths, dst)
+	}
+
+	// iterate over the next paths to repeat the process if not
+	for _, nextPath := range nextPaths {
+		makeSlicePaths(nextPath, depth, slicePaths)
 	}
 }
 
-// use to return timestamp in milliseconds
+// Timestamp in milliseconds
 func makeTimestamp() int64 {
 	return time.Now().UnixNano() / int64(time.Millisecond)
 }
diff --git a/pkg/eth/ipld_retriever.go b/pkg/eth/ipld_retriever.go
index 24a628c3..fe36f991 100644
--- a/pkg/eth/ipld_retriever.go
+++ b/pkg/eth/ipld_retriever.go
@@ -17,6 +17,7 @@
 package eth
 
 import (
+	"database/sql"
 	"fmt"
 	"strconv"
 
@@ -239,7 +240,7 @@ const (
 										)
 									WHERE tx_hash = $1
 									AND transaction_cids.header_id = (SELECT canonical_header_hash(transaction_cids.block_number))`
-	RetrieveStateByPathAndBlockNumberPgStr = `SELECT state_cids.cid, data
+	RetrieveStateByPathAndBlockNumberPgStr = `SELECT cid, data, node_type
 									FROM eth.state_cids
 									INNER JOIN public.blocks ON (
 										state_cids.mh_key = blocks.key
@@ -250,7 +251,7 @@ const (
 									AND node_type != 3
 									ORDER BY state_cids.block_number DESC
 									LIMIT 1`
-	RetrieveStorageByStateLeafKeyAndPathAndBlockNumberPgStr = `SELECT storage_cids.cid, data
+	RetrieveStorageByStateLeafKeyAndPathAndBlockNumberPgStr = `SELECT storage_cids.cid, data, storage_cids.node_type
 									FROM eth.storage_cids
 									INNER JOIN eth.state_cids ON (
 										storage_cids.state_path = state_cids.state_path
@@ -765,9 +766,14 @@ func (r *IPLDRetriever) RetrieveStatesByPathsAndBlockNumber(tx *sqlx.Tx, paths [
 
 	// TODO: fetch all nodes in a single query
 	for _, path := range paths {
-		// Create a result object, select: cid, data
+		// Create a result object, select: cid, data, node_type
 		res := new(nodeInfo)
 		if err := tx.Get(res, RetrieveStateByPathAndBlockNumberPgStr, path, number); err != nil {
+			// we will not find a node for each path
+			if err == sql.ErrNoRows {
+				continue
+			}
+
 			return nil, nil, nil, nil, 0, err
 		}
 
@@ -805,9 +811,14 @@ func (r *IPLDRetriever) RetrieveStorageByStateLeafKeyAndPathsAndBlockNumber(tx *
 
 	// TODO: fetch all nodes in a single query
 	for _, path := range paths {
-		// Create a result object, select: cid, data
+		// Create a result object, select: cid, data, node_type
 		res := new(nodeInfo)
 		if err := tx.Get(res, RetrieveStorageByStateLeafKeyAndPathAndBlockNumberPgStr, stateLeafKey, path, number); err != nil {
+			// we will not find a node for each path
+			if err == sql.ErrNoRows {
+				continue
+			}
+
 			return nil, nil, nil, nil, 0, err
 		}