Limit jstream parse depth

Add bcicen/jstream#15 by vendoring the package.

Sets JSON depth limit to 100 entries in S3 Select.

cmd/postpolicyform.go

@@ -29,10 +29,10 @@ import (
 	"strings"
 	"time"
 
-	"github.com/bcicen/jstream"
 	"github.com/minio/minio-go/v7/pkg/encrypt"
 	"github.com/minio/minio-go/v7/pkg/set"
 	xhttp "github.com/minio/minio/internal/http"
+	"github.com/minio/minio/internal/s3select/jstream"
 )
 
 // startWithConds - map which indicates if a given condition supports starts-with policy operator
@@ -140,7 +140,7 @@ type PostPolicyForm struct {
 func sanitizePolicy(r io.Reader) (io.Reader, error) {
 	var buf bytes.Buffer
 	e := json.NewEncoder(&buf)
-	d := jstream.NewDecoder(r, 0).ObjectAsKVS()
+	d := jstream.NewDecoder(r, 0).ObjectAsKVS().MaxDepth(10)
 	sset := set.NewStringSet()
 	for mv := range d.Stream() {
 		var kvs jstream.KVS

internal/s3select/csv/record.go

@@ -25,8 +25,8 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/bcicen/jstream"
 	csv "github.com/minio/csvparser"
+	"github.com/minio/minio/internal/s3select/jstream"
 	"github.com/minio/minio/internal/s3select/sql"
 )
 

internal/s3select/json/preader.go

@@ -24,7 +24,7 @@ import (
 	"runtime"
 	"sync"
 
-	"github.com/bcicen/jstream"
+	"github.com/minio/minio/internal/s3select/jstream"
 	"github.com/minio/minio/internal/s3select/sql"
 )
 
@@ -185,7 +185,7 @@ func (r *PReader) startReaders() {
 					dst = make([]jstream.KVS, 0, 1000)
 				}
 
-				d := jstream.NewDecoder(bytes.NewBuffer(in.input), 0).ObjectAsKVS()
+				d := jstream.NewDecoder(bytes.NewBuffer(in.input), 0).ObjectAsKVS().MaxDepth(100)
 				stream := d.Stream()
 				all := dst[:0]
 				for mv := range stream {

internal/s3select/json/reader.go

@@ -21,9 +21,8 @@ import (
 	"io"
 	"sync"
 
+	"github.com/minio/minio/internal/s3select/jstream"
 	"github.com/minio/minio/internal/s3select/sql"
-
-	"github.com/bcicen/jstream"
 )
 
 // Limit single document size to 10MiB, 10x the AWS limit:
@@ -84,7 +83,7 @@ func (r *Reader) Close() error {
 // NewReader - creates new JSON reader using readCloser.
 func NewReader(readCloser io.ReadCloser, args *ReaderArgs) *Reader {
 	readCloser = &syncReadCloser{rc: readCloser}
-	d := jstream.NewDecoder(io.LimitReader(readCloser, maxDocumentSize), 0).ObjectAsKVS()
+	d := jstream.NewDecoder(io.LimitReader(readCloser, maxDocumentSize), 0).ObjectAsKVS().MaxDepth(100)
 	return &Reader{
 		args:       args,
 		decoder:    d,

internal/s3select/json/record.go

@@ -26,8 +26,8 @@ import (
 	"strconv"
 	"strings"
 
-	"github.com/bcicen/jstream"
 	csv "github.com/minio/csvparser"
+	"github.com/minio/minio/internal/s3select/jstream"
 	"github.com/minio/minio/internal/s3select/sql"
 )
 

internal/s3select/jstream/LICENSE

@@ -0,0 +1,22 @@
+The MIT License (MIT)
+
+Copyright (c) 2018 Bradley Cicenas
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+

internal/s3select/jstream/README.md

@@ -0,0 +1,116 @@
+<p align="center"><img width="350px" src="jstream.png" alt="jstream"/></p>
+
+#
+
+[![GoDoc](https://godoc.org/github.com/bcicen/jstream?status.svg)](https://godoc.org/github.com/bcicen/jstream)
+
+
+`jstream` is a streaming JSON parser and value extraction library for Go.
+
+Unlike most JSON parsers, `jstream` is document position- and depth-aware -- this enables the extraction of values at a specified depth, eliminating the overhead of allocating encompassing arrays or objects; e.g:
+
+Using the below example document:
+<img width="85%" src="https://bradley.codes/static/img/jstream-levels.gif" alt="jstream"/>
+
+we can choose to extract and act only the objects within the top-level array:
+```go
+f, _ := os.Open("input.json")
+decoder := jstream.NewDecoder(f, 1) // extract JSON values at a depth level of 1
+for mv := range decoder.Stream() {
+  fmt.Printf("%v\n ", mv.Value)
+}
+```
+
+output:
+```
+map[desc:RGB colors:[red green blue]]
+map[desc:CMYK colors:[cyan magenta yellow black]]
+```
+
+likewise, increasing depth level to `3` yields:
+```
+red
+green
+blue
+cyan
+magenta
+yellow
+black
+```
+
+optionally, kev:value pairs can be emitted as an individual struct:
+```go
+decoder := jstream.NewDecoder(f, 2).EmitKV() // enable KV streaming at a depth level of 2
+```
+
+```
+jstream.KV{desc RGB}
+jstream.KV{colors [red green blue]}
+jstream.KV{desc CMYK}
+jstream.KV{colors [cyan magenta yellow black]}
+```
+
+## Installing 
+
+```bash
+go get github.com/bcicen/jstream
+```
+
+## Commandline
+
+`jstream` comes with a cli tool for quick viewing of parsed values from JSON input:
+
+```bash
+jstream -d 1 < input.json
+```
+
+```json
+{"colors":["red","green","blue"],"desc":"RGB"}
+{"colors":["cyan","magenta","yellow","black"],"desc":"CMYK"}
+```
+
+detailed output with `-v` option:
+```bash
+cat input.json | jstream -v -d -1
+
+depth	start	end	type   | value
+2	018	023	string | "RGB"
+3	041	046	string | "red"
+3	048	055	string | "green"
+3	057	063	string | "blue"
+2	039	065	array  | ["red","green","blue"]
+1	004	069	object | {"colors":["red","green","blue"],"desc":"RGB"}
+2	087	093	string | "CMYK"
+3	111	117	string | "cyan"
+3	119	128	string | "magenta"
+3	130	138	string | "yellow"
+3	140	147	string | "black"
+2	109	149	array  | ["cyan","magenta","yellow","black"]
+1	073	153	object | {"colors":["cyan","magenta","yellow","black"],"desc":"CMYK"}
+0	000	155	array  | [{"colors":["red","green","blue"],"desc":"RGB"},{"colors":["cyan","magenta","yellow","black"],"desc":"CMYK"}]
+```
+
+### Options
+
+Opt | Description
+--- | ---
+-d \<n\> | emit values at depth n. if n < 0, all values will be emitted
+-kv | output inner key value pairs as newly formed objects
+-v | output depth and offset details for each value
+-h | display help dialog
+
+## Benchmarks
+
+Obligatory benchmarks performed on files with arrays of objects, where the decoded objects are to be extracted.
+
+Two file sizes are used -- regular (1.6mb, 1000 objects) and large (128mb, 100000 objects)
+
+input size | lib | MB/s | Allocated
+--- | --- | --- | ---
+regular | standard | 97 | 3.6MB
+regular | jstream | 175 | 2.1MB
+large | standard | 92 | 305MB
+large | jstream | 404 | 69MB
+
+In a real world scenario, including initialization and reader overhead from varying blob sizes, performance can be expected as below:
+<img src="https://bradley.codes/static/img/bench.svg" alt="jstream"/>