lewis.moe
Monorepo for Tangled
types: introduce Commit type
this is a backwards compatible structure that is capable of
deserializing both go-git Commit structs and the existing
types.NiceDiff.Commit struct.
Signed-off-by: oppiliappan <me@oppi.li>
authored by
oppiliappan
and committed by
Tangled
da28eba8
ca8217e9
+168
types/commit.go
+168
types/commit.go
···
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package types
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import (
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"bytes"
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"encoding/json"
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"fmt"
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"maps"
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"strings"
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"github.com/go-git/go-git/v5/plumbing"
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"github.com/go-git/go-git/v5/plumbing/object"
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)
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type Commit struct {
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// hash of the commit object.
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Hash plumbing.Hash `json:"hash,omitempty"`
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// author is the original author of the commit.
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Author object.Signature `json:"author"`
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// committer is the one performing the commit, might be different from author.
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Committer object.Signature `json:"committer"`
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// message is the commit message, contains arbitrary text.
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Message string `json:"message"`
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// treehash is the hash of the root tree of the commit.
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Tree string `json:"tree"`
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// parents are the hashes of the parent commits of the commit.
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ParentHashes []plumbing.Hash `json:"parent_hashes,omitempty"`
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// pgpsignature is the pgp signature of the commit.
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PGPSignature string `json:"pgp_signature,omitempty"`
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// mergetag is the embedded tag object when a merge commit is created by
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// merging a signed tag.
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MergeTag string `json:"merge_tag,omitempty"`
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// changeid is a unique identifier for the change (e.g., gerrit change-id).
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ChangeId string `json:"change_id,omitempty"`
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// extraheaders contains additional headers not captured by other fields.
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ExtraHeaders map[string][]byte `json:"extra_headers,omitempty"`
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// deprecated: kept for backwards compatibility with old json format.
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This string `json:"this,omitempty"`
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// deprecated: kept for backwards compatibility with old json format.
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Parent string `json:"parent,omitempty"`
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}
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// types.Commit is an unify two commit structs:
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// - git.object.Commit from
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// - types.NiceDiff.commit
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//
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// to do this in backwards compatible fashion, we define the base struct
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// to use the same fields as NiceDiff.Commit, and then we also unmarshal
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// the struct fields from go-git structs, this custom unmarshal makes sense
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// of both representations and unifies them to have maximal data in either
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// form.
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func (c *Commit) UnmarshalJSON(data []byte) error {
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type Alias Commit
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aux := &struct {
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*object.Commit
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*Alias
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}{
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Alias: (*Alias)(c),
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}
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if err := json.Unmarshal(data, aux); err != nil {
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return err
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}
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c.FromGoGitCommit(aux.Commit)
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return nil
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}
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// fill in as much of Commit as possible from the given go-git commit
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func (c *Commit) FromGoGitCommit(gc *object.Commit) {
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if gc == nil {
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return
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}
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if c.Hash.IsZero() {
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c.Hash = gc.Hash
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}
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if c.This == "" {
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c.This = gc.Hash.String()
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}
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if isEmptySignature(c.Author) {
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c.Author = gc.Author
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}
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if isEmptySignature(c.Committer) {
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c.Committer = gc.Committer
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}
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if c.Message == "" {
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c.Message = gc.Message
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}
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if c.Tree == "" {
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c.Tree = gc.TreeHash.String()
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}
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if c.PGPSignature == "" {
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c.PGPSignature = gc.PGPSignature
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}
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if c.MergeTag == "" {
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c.MergeTag = gc.MergeTag
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}
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if len(c.ParentHashes) == 0 {
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c.ParentHashes = gc.ParentHashes
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}
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if c.Parent == "" && len(gc.ParentHashes) > 0 {
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c.Parent = gc.ParentHashes[0].String()
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}
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if len(c.ExtraHeaders) == 0 {
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c.ExtraHeaders = make(map[string][]byte)
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maps.Copy(c.ExtraHeaders, gc.ExtraHeaders)
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}
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if c.ChangeId == "" {
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if v, ok := gc.ExtraHeaders["change-id"]; ok {
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c.ChangeId = string(v)
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}
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}
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}
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func isEmptySignature(s object.Signature) bool {
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return s.Email == "" && s.Name == "" && s.When.IsZero()
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}
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// produce a verifiable payload from this commit's metadata
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func (c *Commit) Payload() string {
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author := bytes.NewBuffer([]byte{})
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c.Author.Encode(author)
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committer := bytes.NewBuffer([]byte{})
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c.Committer.Encode(committer)
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payload := strings.Builder{}
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fmt.Fprintf(&payload, "tree %s\n", c.Tree)
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if len(c.ParentHashes) > 0 {
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for _, p := range c.ParentHashes {
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fmt.Fprintf(&payload, "parent %s\n", p.String())
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}
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} else {
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// present for backwards compatibility
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fmt.Fprintf(&payload, "parent %s\n", c.Parent)
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}
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fmt.Fprintf(&payload, "author %s\n", author.String())
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fmt.Fprintf(&payload, "committer %s\n", committer.String())
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if c.ChangeId != "" {
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fmt.Fprintf(&payload, "change-id %s\n", c.ChangeId)
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} else if v, ok := c.ExtraHeaders["change-id"]; ok {
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fmt.Fprintf(&payload, "change-id %s\n", string(v))
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}
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fmt.Fprintf(&payload, "\n%s", c.Message)
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return payload.String()
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}