Move large object to own file

Author: porsager

src/index.js

@@ -1,6 +1,5 @@
 import os from 'os'
 import fs from 'fs'
-import Stream from 'stream'
 
 import {
   mergeUserTypes,
@@ -21,6 +20,7 @@ import { Query, CLOSE } from './query.js'
 import Queue from './queue.js'
 import { Errors, PostgresError } from './errors.js'
 import Subscribe from './subscribe.js'
+import largeObject from './large.js'
 
 Object.assign(Postgres, {
   PostgresError,
@@ -56,7 +56,7 @@ function Postgres(a, b) {
 
   Object.assign(sql, {
     get parameters() { return options.parameters },
-    largeObject,
+    largeObject: largeObject.bind(null, sql),
     subscribe,
     CLOSE,
     END: CLOSE,
@@ -246,75 +246,6 @@ function Postgres(a, b) {
     }
   }
 
-  function largeObject(oid, mode = 0x00020000 | 0x00040000) {
-    return new Promise(async(resolve, reject) => {
-      await sql.begin(async sql => {
-        let finish
-        !oid && ([{ oid }] = await sql`select lo_creat(-1) as oid`)
-        const [{ fd }] = await sql`select lo_open(${ oid }, ${ mode }) as fd`
-
-        const lo = {
-          writable,
-          readable,
-          close     : () => sql`select lo_close(${ fd })`.then(finish),
-          tell      : () => sql`select lo_tell64(${ fd })`,
-          read      : (x) => sql`select loread(${ fd }, ${ x }) as data`,
-          write     : (x) => sql`select lowrite(${ fd }, ${ x })`,
-          truncate  : (x) => sql`select lo_truncate64(${ fd }, ${ x })`,
-          seek      : (x, whence = 0) => sql`select lo_lseek64(${ fd }, ${ x }, ${ whence })`,
-          size      : () => sql`
-            select
-              lo_lseek64(${ fd }, location, 0) as position,
-              seek.size
-            from (
-              select
-                lo_lseek64($1, 0, 2) as size,
-                tell.location
-              from (select lo_tell64($1) as location) tell
-            ) seek
-          `
-        }
-
-        resolve(lo)
-
-        return new Promise(async r => finish = r)
-
-        async function readable({
-          highWaterMark = 2048 * 8,
-          start = 0,
-          end = Infinity
-        } = {}) {
-          let max = end - start
-          start && await lo.seek(start)
-          return new Stream.Readable({
-            highWaterMark,
-            async read(size) {
-              const l = size > max ? size - max : size
-              max -= size
-              const [{ data }] = await lo.read(l)
-              this.push(data)
-              if (data.length < size)
-                this.push(null)
-            }
-          })
-        }
-
-        async function writable({
-          highWaterMark = 2048 * 8,
-          start = 0
-        } = {}) {
-          start && await lo.seek(start)
-          return new Stream.Writable({
-            highWaterMark,
-            write(chunk, encoding, callback) {
-              lo.write(chunk).then(() => callback(), callback)
-            }
-          })
-        }
-      }).catch(reject)
-    })
-  }
-
   function json(x) {
     return new Parameter(x, 3802)
   }

src/large.js

@@ -0,0 +1,70 @@
+import Stream from 'stream'
+
+export default function largeObject(sql, oid, mode = 0x00020000 | 0x00040000) {
+  return new Promise(async(resolve, reject) => {
+    await sql.begin(async sql => {
+      let finish
+      !oid && ([{ oid }] = await sql`select lo_creat(-1) as oid`)
+      const [{ fd }] = await sql`select lo_open(${ oid }, ${ mode }) as fd`
+
+      const lo = {
+        writable,
+        readable,
+        close     : () => sql`select lo_close(${ fd })`.then(finish),
+        tell      : () => sql`select lo_tell64(${ fd })`,
+        read      : (x) => sql`select loread(${ fd }, ${ x }) as data`,
+        write     : (x) => sql`select lowrite(${ fd }, ${ x })`,
+        truncate  : (x) => sql`select lo_truncate64(${ fd }, ${ x })`,
+        seek      : (x, whence = 0) => sql`select lo_lseek64(${ fd }, ${ x }, ${ whence })`,
+        size      : () => sql`
+          select
+            lo_lseek64(${ fd }, location, 0) as position,
+            seek.size
+          from (
+            select
+              lo_lseek64($1, 0, 2) as size,
+              tell.location
+            from (select lo_tell64($1) as location) tell
+          ) seek
+        `
+      }
+
+      resolve(lo)
+
+      return new Promise(async r => finish = r)
+
+      async function readable({
+        highWaterMark = 2048 * 8,
+        start = 0,
+        end = Infinity
+      } = {}) {
+        let max = end - start
+        start && await lo.seek(start)
+        return new Stream.Readable({
+          highWaterMark,
+          async read(size) {
+            const l = size > max ? size - max : size
+            max -= size
+            const [{ data }] = await lo.read(l)
+            this.push(data)
+            if (data.length < size)
+              this.push(null)
+          }
+        })
+      }
+
+      async function writable({
+        highWaterMark = 2048 * 8,
+        start = 0
+      } = {}) {
+        start && await lo.seek(start)
+        return new Stream.Writable({
+          highWaterMark,
+          write(chunk, encoding, callback) {
+            lo.write(chunk).then(() => callback(), callback)
+          }
+        })
+      }
+    }).catch(reject)
+  })
+}