Merge pull request #884 from go-kivik/revisions

Begin support for new_edits=false & _revisions
go-kivik · Feb 15, 2024 · d888232 · d888232
2 parents 62d8c26 + 0954825
commit d888232
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Showing 4 changed files with 167 additions and 30 deletions.
diff --git a/x/sqlite/db.go b/x/sqlite/db.go
@@ -71,24 +71,51 @@ func (d *db) Put(ctx context.Context, docID string, doc interface{}, options dri
 	defer tx.Rollback()
 
 	if newEdits, _ := opts["new_edits"].(bool); !newEdits {
-		if docRev == "" {
-			return "", &internal.Error{Status: http.StatusBadRequest, Message: "When `new_edits: false`, the document needs `_rev` or `_revisions` specified"}
-		}
-		rev, err := parseRev(docRev)
-		if err != nil {
-			return "", err
-		}
-		_, err = tx.ExecContext(ctx, fmt.Sprintf(`
+		var rev revision
+		if data.Revisions.Start != 0 {
+			stmt, err := tx.PrepareContext(ctx, fmt.Sprintf(`
+				INSERT INTO %[1]q (id, rev, rev_id, parent_rev, parent_rev_id)
+				VALUES ($1, $2, $3, $4, $5)
+			`, d.name+"_revs"))
+			if err != nil {
+				return "", err
+			}
+			defer stmt.Close()
+
+			var (
+				parentRev   *int
+				parentRevID *string
+			)
+			for _, r := range data.Revisions.revs() {
+				r := r
+				_, err := stmt.ExecContext(ctx, data.ID, r.rev, r.id, parentRev, parentRevID)
+				if err != nil {
+					return "", err
+				}
+				parentRev = &r.rev
+				parentRevID = &r.id
+			}
+			rev = data.Revisions.leaf()
+		} else {
+			if docRev == "" {
+				return "", &internal.Error{Status: http.StatusBadRequest, Message: "When `new_edits: false`, the document needs `_rev` or `_revisions` specified"}
+			}
+			rev, err = parseRev(docRev)
+			if err != nil {
+				return "", err
+			}
+			_, err = tx.ExecContext(ctx, fmt.Sprintf(`
 			INSERT INTO %[1]q (id, rev, rev_id)
 			VALUES ($1, $2, $3)
 		`, d.name+"_revs"), docID, rev.rev, rev.id)
-		if err != nil {
-			var sqliteErr *sqlite.Error
-			// A conflict here can be ignored, as we're not actually writing the
-			// document, and the rev can theoretically be updated without the doc
-			// during replication.
-			if !errors.As(err, &sqliteErr) || sqliteErr.Code() != sqlite3.SQLITE_CONSTRAINT_UNIQUE {
-				return "", err
+			if err != nil {
+				var sqliteErr *sqlite.Error
+				// A conflict here can be ignored, as we're not actually writing the
+				// document, and the rev can theoretically be updated without the doc
+				// during replication.
+				if !errors.As(err, &sqliteErr) || sqliteErr.Code() != sqlite3.SQLITE_CONSTRAINT_UNIQUE {
+					return "", err
+				}
 			}
 		}
 		var newRev string
@@ -139,7 +166,7 @@ func (d *db) Put(ctx context.Context, docID string, doc interface{}, options dri
 		FROM %[1]q
 		WHERE id = $1
 		RETURNING rev, rev_id
-	`, d.name+"_revs"), data.ID, data.Rev, curRevRev, curRevID).Scan(&r.rev, &r.id)
+	`, d.name+"_revs"), data.ID, data.RevID, curRevRev, curRevID).Scan(&r.rev, &r.id)
 	if err != nil {
 		return "", err
 	}
@@ -387,7 +414,7 @@ func (d *db) Delete(ctx context.Context, docID string, options driver.Options) (
 		FROM %[1]q
 		WHERE id = $1
 		RETURNING rev, rev_id
-	`, d.name+"_revs"), data.ID, data.Rev, curRevRev, curRevID).Scan(&r.rev, &r.id)
+	`, d.name+"_revs"), data.ID, data.RevID, curRevRev, curRevID).Scan(&r.rev, &r.id)
 	if err != nil {
 		return "", err
 	}

diff --git a/x/sqlite/db_test.go b/x/sqlite/db_test.go
@@ -383,6 +383,47 @@ func TestDBPut(t *testing.T) {
 				}
 			},
 		},
+		{
+			name:  "new_edits=false, with _revisions",
+			docID: "foo",
+			doc: map[string]interface{}{
+				"_revisions": map[string]interface{}{
+					"ids":   []string{"ghi", "def", "abc"},
+					"start": 3,
+				},
+				"foo": "bar",
+			},
+			options: kivik.Param("new_edits", false),
+			wantRev: "3-ghi",
+			wantRevs: []leaf{
+				{
+					ID:    "foo",
+					Rev:   1,
+					RevID: "abc",
+				},
+				{
+					ID:          "foo",
+					Rev:         2,
+					RevID:       "def",
+					ParentRev:   &[]int{1}[0],
+					ParentRevID: &[]string{"abc"}[0],
+				},
+				{
+					ID:          "foo",
+					Rev:         3,
+					RevID:       "ghi",
+					ParentRev:   &[]int{2}[0],
+					ParentRevID: &[]string{"def"}[0],
+				},
+			},
+		},
+		/*
+		 - _revisions and _rev conflict
+		 - _revisions and rev query parameter conflict
+		 - _revisions replay
+		 - _revisions partial replay (some revs already exist)
+		 - _revisions with some revs and docs already exist
+		*/
 	}
 
 	for _, tt := range tests {

diff --git a/x/sqlite/json.go b/x/sqlite/json.go
@@ -56,10 +56,31 @@ func parseRev(s string) (revision, error) {
 
 // docData represents the document id, rev, deleted status, etc.
 type docData struct {
-	ID      string `json:"_id"`
-	Rev     string `json:"_rev"`
-	Deleted bool   `json:"_deleted"`
-	Doc     []byte
+	ID string `json:"_id"`
+	// RevID is the calculated revision ID, not the actual _rev field from the
+	// document.
+	RevID     string   `json:"-"`
+	Revisions revsInfo `json:"_revisions"`
+	Deleted   bool     `json:"_deleted"`
+	Doc       []byte
+}
+
+type revsInfo struct {
+	Start int      `json:"start"`
+	IDs   []string `json:"ids"`
+}
+
+func (r *revsInfo) revs() []revision {
+	revs := make([]revision, len(r.IDs))
+	for i, id := range r.IDs {
+		revs[len(r.IDs)-i-1] = revision{rev: r.Start - i, id: id}
+	}
+	return revs
+}
+
+// leaf returns the leaf revision of the revsInfo.
+func (r *revsInfo) leaf() revision {
+	return revision{rev: r.Start, id: r.IDs[0]}
 }
 
 // prepareDoc prepares the doc for insertion. It returns the new docID, rev, and
@@ -93,7 +114,7 @@ func prepareDoc(docID string, doc interface{}) (*docData, error) {
 	if _, err := io.Copy(h, bytes.NewReader(b)); err != nil {
 		return nil, err
 	}
-	data.Rev = hex.EncodeToString(h.Sum(nil))
+	data.RevID = hex.EncodeToString(h.Sum(nil))
 	data.Doc = b
 	return data, nil
 }

diff --git a/x/sqlite/json_test.go b/x/sqlite/json_test.go
@@ -34,8 +34,8 @@ func Test_prepareDoc(t *testing.T) {
 			name: "no rev in document",
 			doc:  map[string]string{"foo": "bar"},
 			want: &docData{
-				Rev: "9bb58f26192e4ba00f01e2e7b136bbd8",
-				Doc: []byte(`{"foo":"bar"}`),
+				RevID: "9bb58f26192e4ba00f01e2e7b136bbd8",
+				Doc:   []byte(`{"foo":"bar"}`),
 			},
 		},
 		{
@@ -45,18 +45,18 @@ func Test_prepareDoc(t *testing.T) {
 				"foo":  "bar",
 			},
 			want: &docData{
-				Rev: "9bb58f26192e4ba00f01e2e7b136bbd8",
-				Doc: []byte(`{"foo":"bar"}`),
+				RevID: "9bb58f26192e4ba00f01e2e7b136bbd8",
+				Doc:   []byte(`{"foo":"bar"}`),
 			},
 		},
 		{
 			name:  "add docID",
 			docID: "foo",
 			doc:   map[string]string{"foo": "bar"},
 			want: &docData{
-				ID:  "foo",
-				Rev: "9bb58f26192e4ba00f01e2e7b136bbd8",
-				Doc: []byte(`{"foo":"bar"}`),
+				ID:    "foo",
+				RevID: "9bb58f26192e4ba00f01e2e7b136bbd8",
+				Doc:   []byte(`{"foo":"bar"}`),
 			},
 		},
 		{
@@ -67,7 +67,7 @@ func Test_prepareDoc(t *testing.T) {
 				"foo":      "bar",
 			},
 			want: &docData{
-				Rev:     "6872a0fc474ada5c46ce054b92897063",
+				RevID:   "6872a0fc474ada5c46ce054b92897063",
 				Doc:     []byte(`{"_deleted":true,"foo":"bar"}`),
 				Deleted: true,
 			},
@@ -169,3 +169,51 @@ func Test_extractRev(t *testing.T) {
 		})
 	}
 }
+
+func Test_revsInfo_revs(t *testing.T) {
+	tests := []struct {
+		name string
+		ri   revsInfo
+		want []string
+	}{
+		{
+			name: "empty",
+			ri:   revsInfo{},
+			want: []string{},
+		},
+		{
+			name: "single",
+			ri: revsInfo{
+				Start: 1,
+				IDs:   []string{"a"},
+			},
+			want: []string{
+				"1-a",
+			},
+		},
+		{
+			name: "multiple",
+			ri: revsInfo{
+				Start: 8,
+				IDs:   []string{"z", "y", "x"},
+			},
+			want: []string{
+				"6-x",
+				"7-y",
+				"8-z",
+			},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := []string{}
+			for _, r := range tt.ri.revs() {
+				got = append(got, r.String())
+			}
+			if d := cmp.Diff(tt.want, got); d != "" {
+				t.Errorf(d)
+			}
+		})
+	}
+}