Cache columns for prepared statements

porsager · porsager · commit 7a02b9446227 · 2019-11-24T14:24:12.000+01:00
diff --git a/lib/backend.js b/lib/backend.js
@@ -16,7 +16,6 @@ function Backend({
   onnotify
 }) {
   let result = null
-  let columns = null
   let rows = 0
 
   const backend = Object.entries({
@@ -85,7 +84,6 @@ function Backend({
       : result
     )
     result = null
-    columns = null
     rows = 0
   }
 
@@ -99,8 +97,8 @@ function Backend({
     let column
 
     const row = {}
-    for (let i = 0; i < columns.length; i++) {
-      column = columns[i]
+    for (let i = 0; i < backend.query.statement.columns.length; i++) {
+      column = backend.query.statement.columns[i]
       length = x.readInt32BE(index)
       index += 4
 
@@ -172,18 +170,22 @@ function Backend({
   }
 
   function RowDescription(x) {
+    result = []
+    rows = 0
+
+    if (backend.query.statement.columns)
+      return
+
     const length = x.readInt16BE(5)
     let index = 7
     let start
 
-    columns = Array(length)
-    result = []
-    rows = 0
+    backend.query.statement.columns = Array(length)
 
     for (let i = 0; i < length; ++i) {
       start = index
       while (x[index++] !== 0);
-      columns[i] = {
+      backend.query.statement.columns[i] = {
         n: transform(x.utf8Slice(start, index - 1)),
         p: parsers[x.readInt32BE(index + 6)]
       }
diff --git a/lib/connection.js b/lib/connection.js
@@ -93,24 +93,25 @@ export default function Connection(options = {}) {
       : (backend.query = query)
 
     const buffer = statements.has(sig)
-      ? prepared(statements.get(sig), args)
-      : prepare(sig, str, args)
+      ? prepared(statements.get(sig), args, query)
+      : prepare(sig, str, args, query)
 
     connection.ready
       ? socket.write(buffer)
       : (messages.push(buffer), socket.connect())
   }
 
-  function prepared(name, args) {
-    return frontend.Bind(name, args)
+  function prepared(statement, args, query) {
+    query.statement = statement
+    return frontend.Bind(statement.name, args)
   }
 
-  function prepare(sig, str, args) {
-    const name = sig ? 'p' + id++ : ''
-    sig && statements.set(sig, name)
+  function prepare(sig, str, args, query) {
+    query.statement = { name: sig ? 'p' + id++ : '' }
+    sig && statements.set(sig, query.statement)
     return Buffer.concat([
-      frontend.Parse(name, str, args),
-      frontend.Bind(name, args)
+      frontend.Parse(query.statement.name, str, args),
+      frontend.Bind(query.statement.name, args)
     ])
   }
 
