Initial commit

Author: mcy

CONTRIBUTING.md

@@ -0,0 +1,28 @@
+# How to Contribute
+
+We'd love to accept your patches and contributions to this project. There are
+just a few small guidelines you need to follow.
+
+## Contributor License Agreement
+
+Contributions to this project must be accompanied by a Contributor License
+Agreement. You (or your employer) retain the copyright to your contribution;
+this simply gives us permission to use and redistribute your contributions as
+part of the project. Head over to <https://cla.developers.google.com/> to see
+your current agreements on file or to sign a new one.
+
+You generally only need to submit a CLA once, so if you've already submitted one
+(even if it was for a different project), you probably don't need to do it
+again.
+
+## Code Reviews
+
+All submissions, including submissions by project members, require review. We
+use GitHub pull requests for this purpose. Consult
+[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
+information on using pull requests.
+
+## Community Guidelines
+
+This project follows [Google's Open Source Community
+Guidelines](https://opensource.google/conduct/).

LICENSE

@@ -0,0 +1,202 @@
+
+                                 Apache License
+                           Version 2.0, January 2004
+                        http://www.apache.org/licenses/
+
+   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+   1. Definitions.
+
+      "License" shall mean the terms and conditions for use, reproduction,
+      and distribution as defined by Sections 1 through 9 of this document.
+
+      "Licensor" shall mean the copyright owner or entity authorized by
+      the copyright owner that is granting the License.
+
+      "Legal Entity" shall mean the union of the acting entity and all
+      other entities that control, are controlled by, or are under common
+      control with that entity. For the purposes of this definition,
+      "control" means (i) the power, direct or indirect, to cause the
+      direction or management of such entity, whether by contract or
+      otherwise, or (ii) ownership of fifty percent (50%) or more of the
+      outstanding shares, or (iii) beneficial ownership of such entity.
+
+      "You" (or "Your") shall mean an individual or Legal Entity
+      exercising permissions granted by this License.
+
+      "Source" form shall mean the preferred form for making modifications,
+      including but not limited to software source code, documentation
+      source, and configuration files.
+
+      "Object" form shall mean any form resulting from mechanical
+      transformation or translation of a Source form, including but
+      not limited to compiled object code, generated documentation,
+      and conversions to other media types.
+
+      "Work" shall mean the work of authorship, whether in Source or
+      Object form, made available under the License, as indicated by a
+      copyright notice that is included in or attached to the work
+      (an example is provided in the Appendix below).
+
+      "Derivative Works" shall mean any work, whether in Source or Object
+      form, that is based on (or derived from) the Work and for which the
+      editorial revisions, annotations, elaborations, or other modifications
+      represent, as a whole, an original work of authorship. For the purposes
+      of this License, Derivative Works shall not include works that remain
+      separable from, or merely link (or bind by name) to the interfaces of,
+      the Work and Derivative Works thereof.
+
+      "Contribution" shall mean any work of authorship, including
+      the original version of the Work and any modifications or additions
+      to that Work or Derivative Works thereof, that is intentionally
+      submitted to Licensor for inclusion in the Work by the copyright owner
+      or by an individual or Legal Entity authorized to submit on behalf of
+      the copyright owner. For the purposes of this definition, "submitted"
+      means any form of electronic, verbal, or written communication sent
+      to the Licensor or its representatives, including but not limited to
+      communication on electronic mailing lists, source code control systems,
+      and issue tracking systems that are managed by, or on behalf of, the
+      Licensor for the purpose of discussing and improving the Work, but
+      excluding communication that is conspicuously marked or otherwise
+      designated in writing by the copyright owner as "Not a Contribution."
+
+      "Contributor" shall mean Licensor and any individual or Legal Entity
+      on behalf of whom a Contribution has been received by Licensor and
+      subsequently incorporated within the Work.
+
+   2. Grant of Copyright License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      copyright license to reproduce, prepare Derivative Works of,
+      publicly display, publicly perform, sublicense, and distribute the
+      Work and such Derivative Works in Source or Object form.
+
+   3. Grant of Patent License. Subject to the terms and conditions of
+      this License, each Contributor hereby grants to You a perpetual,
+      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+      (except as stated in this section) patent license to make, have made,
+      use, offer to sell, sell, import, and otherwise transfer the Work,
+      where such license applies only to those patent claims licensable
+      by such Contributor that are necessarily infringed by their
+      Contribution(s) alone or by combination of their Contribution(s)
+      with the Work to which such Contribution(s) was submitted. If You
+      institute patent litigation against any entity (including a
+      cross-claim or counterclaim in a lawsuit) alleging that the Work
+      or a Contribution incorporated within the Work constitutes direct
+      or contributory patent infringement, then any patent licenses
+      granted to You under this License for that Work shall terminate
+      as of the date such litigation is filed.
+
+   4. Redistribution. You may reproduce and distribute copies of the
+      Work or Derivative Works thereof in any medium, with or without
+      modifications, and in Source or Object form, provided that You
+      meet the following conditions:
+
+      (a) You must give any other recipients of the Work or
+          Derivative Works a copy of this License; and
+
+      (b) You must cause any modified files to carry prominent notices
+          stating that You changed the files; and
+
+      (c) You must retain, in the Source form of any Derivative Works
+          that You distribute, all copyright, patent, trademark, and
+          attribution notices from the Source form of the Work,
+          excluding those notices that do not pertain to any part of
+          the Derivative Works; and
+
+      (d) If the Work includes a "NOTICE" text file as part of its
+          distribution, then any Derivative Works that You distribute must
+          include a readable copy of the attribution notices contained
+          within such NOTICE file, excluding those notices that do not
+          pertain to any part of the Derivative Works, in at least one
+          of the following places: within a NOTICE text file distributed
+          as part of the Derivative Works; within the Source form or
+          documentation, if provided along with the Derivative Works; or,
+          within a display generated by the Derivative Works, if and
+          wherever such third-party notices normally appear. The contents
+          of the NOTICE file are for informational purposes only and
+          do not modify the License. You may add Your own attribution
+          notices within Derivative Works that You distribute, alongside
+          or as an addendum to the NOTICE text from the Work, provided
+          that such additional attribution notices cannot be construed
+          as modifying the License.
+
+      You may add Your own copyright statement to Your modifications and
+      may provide additional or different license terms and conditions
+      for use, reproduction, or distribution of Your modifications, or
+      for any such Derivative Works as a whole, provided Your use,
+      reproduction, and distribution of the Work otherwise complies with
+      the conditions stated in this License.
+
+   5. Submission of Contributions. Unless You explicitly state otherwise,
+      any Contribution intentionally submitted for inclusion in the Work
+      by You to the Licensor shall be under the terms and conditions of
+      this License, without any additional terms or conditions.
+      Notwithstanding the above, nothing herein shall supersede or modify
+      the terms of any separate license agreement you may have executed
+      with Licensor regarding such Contributions.
+
+   6. Trademarks. This License does not grant permission to use the trade
+      names, trademarks, service marks, or product names of the Licensor,
+      except as required for reasonable and customary use in describing the
+      origin of the Work and reproducing the content of the NOTICE file.
+
+   7. Disclaimer of Warranty. Unless required by applicable law or
+      agreed to in writing, Licensor provides the Work (and each
+      Contributor provides its Contributions) on an "AS IS" BASIS,
+      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+      implied, including, without limitation, any warranties or conditions
+      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
+      PARTICULAR PURPOSE. You are solely responsible for determining the
+      appropriateness of using or redistributing the Work and assume any
+      risks associated with Your exercise of permissions under this License.
+
+   8. Limitation of Liability. In no event and under no legal theory,
+      whether in tort (including negligence), contract, or otherwise,
+      unless required by applicable law (such as deliberate and grossly
+      negligent acts) or agreed to in writing, shall any Contributor be
+      liable to You for damages, including any direct, indirect, special,
+      incidental, or consequential damages of any character arising as a
+      result of this License or out of the use or inability to use the
+      Work (including but not limited to damages for loss of goodwill,
+      work stoppage, computer failure or malfunction, or any and all
+      other commercial damages or losses), even if such Contributor
+      has been advised of the possibility of such damages.
+
+   9. Accepting Warranty or Additional Liability. While redistributing
+      the Work or Derivative Works thereof, You may choose to offer,
+      and charge a fee for, acceptance of support, warranty, indemnity,
+      or other liability obligations and/or rights consistent with this
+      License. However, in accepting such obligations, You may act only
+      on Your own behalf and on Your sole responsibility, not on behalf
+      of any other Contributor, and only if You agree to indemnify,
+      defend, and hold each Contributor harmless for any liability
+      incurred by, or claims asserted against, such Contributor by reason
+      of your accepting any such warranty or additional liability.
+
+   END OF TERMS AND CONDITIONS
+
+   APPENDIX: How to apply the Apache License to your work.
+
+      To apply the Apache License to your work, attach the following
+      boilerplate notice, with the fields enclosed by brackets "[]"
+      replaced with your own identifying information. (Don't include
+      the brackets!)  The text should be enclosed in the appropriate
+      comment syntax for the file format. We also recommend that a
+      file or class name and description of purpose be included on the
+      same "printed page" as the copyright notice for easier
+      identification within third-party archives.
+
+   Copyright [yyyy] [name of copyright owner]
+
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+       http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.

README.md

@@ -0,0 +1,50 @@
+# Protoscope
+
+*Protobuf + Rotoscope*
+
+Protoscope is a simple, human-editable language for representing and emitting
+the [Protobuf wire format](https://developers.google.com/protocol-buffers/docs/encoding).
+It is inspired by, and is significantly based on,
+[DER ASCII](https://github.com/google/der-ascii), a similar tool for working with
+DER and BER, wire formats of ASN.1.
+
+Unlike most Protobuf tools, it is completely ignorant of schemata specified in `.proto`
+files; it has just enough knowledge of the wire format to provide primitives for 
+constructing messages (such as field tags, varints, and length prefixes). A disassembler
+is included that uses heuristics to try convert encoded Protobuf into Protoscope,
+although the heuristics are necessarily imperfect.
+
+We provide the Go package `github.com/google/protoscope`, as well as the `protoscope`
+tool, which can be installed with the Go tool via
+
+    go install github.com/google/protoscope/cmd/protoscope...@latest
+
+These tools may be used to create test inputs by taking an existing proto,
+dissassembling with `protoscope`, making edits, and then reassembling with
+`protoscope -s`. This avoids having to manually fix up all the length prefixes.
+They may also be used to inspect proto files (or things that look like them.)
+
+For the language specification and basic examples, see [language.txt](/language.txt).
+
+## Backwards compatibility
+
+The Protoscope language itself may be extended over time, but the intention is
+for extensions to be backwards-compatible. Specifically:
+
+* The command-line interface to `protoscope` will remain compatible, though new
+  options may be added in the future.
+
+* Previously valid Protoscope will remain valid and produce the same output.
+  In particular, checking in test data as Protoscope text should be future-proof.
+
+* Previously invalid Protoscope may become valid in the future if
+  the language is extended.
+
+* Disassembly is necessarily a heuristic, so its output *may* change over time,
+  but it is guaranteed to produce Protoscope output that will reassemble to the
+  original byte string. `protoscope | protoscope -s` is always equivalent to
+  `cat`.
+
+## Disclaimer
+
+This is not an official Google project.

cmd/protoscope/main.go

@@ -0,0 +1,103 @@
+// Copyright 2022 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+
+package main
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"os"
+
+	_ "embed"
+
+	"github.com/google/protoscope"
+)
+
+var (
+	outPath = flag.String("o", "", "output file to use (defaults to stdout)")
+	assemble = flag.Bool("s", false, "whether to treat the input as a Protoscope source file")
+
+	noQuotedStrings = flag.Bool("no-quoted-strings", false, "assume no fields in the input proto are strings")
+	allFieldsAreMessages = flag.Bool("all-fields-are-messages", false, "try really hard to disassemble all fields as messages")
+)
+
+func main() {
+	flag.Usage = func() {
+		fmt.Fprintf(os.Stderr, "Usage: %s [OPTION...] [INPUT]\n", os.Args[0])
+		fmt.Fprintf(os.Stderr, "Assemble a Protoscope file to binary, or inspect binary data as Protoscope text.\n\n")
+		flag.PrintDefaults()
+		fmt.Fprintf(os.Stderr, "\n%s\n", protoscope.LanguageText)
+	}
+
+	flag.Parse()
+
+	if flag.NArg() > 1 {
+		flag.Usage()
+		os.Exit(1)
+	}
+
+	inPath := ""
+	inFile := os.Stdin
+	if flag.NArg() == 1 {
+		inPath = flag.Arg(0)
+		var err error
+		inFile, err = os.Open(inPath)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error opening %s: %s\n", inPath, err)
+			os.Exit(1)
+		}
+		defer inFile.Close()
+	}
+
+	inBytes, err := io.ReadAll(inFile)
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "Error reading input: %s\n", err)
+		os.Exit(1)
+	}
+
+	var outBytes []byte
+	if *assemble {
+		scanner := protoscope.NewScanner(string(inBytes))
+		scanner.SetFile(inPath)
+
+		outBytes, err = scanner.Exec()
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Syntax error: %s\n", err)
+			os.Exit(1)
+		}
+	} else {
+		outBytes = []byte(protoscope.Write(inBytes, protoscope.WriterOptions{
+			NoQuotedStrings: *noQuotedStrings,
+			AllFieldsAreMessages: *allFieldsAreMessages,
+		}))
+	}
+
+	outFile := os.Stdout
+	if *outPath != "" {
+		var err error
+		outFile, err = os.Create(*outPath)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "Error opening %s: %s\n", *outPath, err)
+			os.Exit(1)
+		}
+		defer outFile.Close()
+	}
+	
+	if _, err = outFile.Write(outBytes); err != nil {
+		fmt.Fprintf(os.Stderr, "Error writing output: %s\n", err)
+		os.Exit(1)
+	}
+}

go.mod

@@ -0,0 +1,3 @@
+module github.com/google/protoscope
+
+go 1.18