Add `countenvelope` encoder with marshal/unmarshal support, buffer pool integration, and tests; improve error messages for subscription validation

pkg/encoders/envelopes/countenvelope/countenvelope.go

@@ -0,0 +1,206 @@
+// Package countenvelope is an encoder for the COUNT request (client) and
+// response (relay) message types.
+package countenvelope
+
+import (
+	"bytes"
+	"io"
+
+	"lol.mleku.dev/chk"
+	"lol.mleku.dev/errorf"
+	"next.orly.dev/pkg/encoders/envelopes"
+	"next.orly.dev/pkg/encoders/filter"
+	"next.orly.dev/pkg/encoders/ints"
+	"next.orly.dev/pkg/encoders/text"
+	"next.orly.dev/pkg/interfaces/codec"
+)
+
+// L is the label associated with this type of codec.Envelope.
+const L = "COUNT"
+
+// Request is a COUNT envelope sent by a client to request a count of results.
+// This is a stupid idea because it costs as much processing as fetching the
+// events, but doesn't provide the means to actually get them (the HTTP API
+// /filter does this by returning the actual event Ids).
+type Request struct {
+	Subscription []byte
+	Filters      filter.S
+}
+
+var _ codec.Envelope = (*Request)(nil)
+
+// New creates a new Request with a standard style subscription.Id and empty filter.
+func New() *Request { return new(Request) }
+
+// NewRequest creates a new Request with a provided subscription.Id and
+// filter.T.
+func NewRequest(id []byte, filters filter.S) *Request {
+	return &Request{
+		Subscription: id,
+		Filters:      filters,
+	}
+}
+
+// Label returns the label of a CLOSED envelope.
+func (en *Request) Label() string { return L }
+
+// Write the Request to a provided io.Writer.
+func (en *Request) Write(w io.Writer) (err error) {
+	var b []byte
+	b = en.Marshal(b)
+	_, err = w.Write(b)
+	return
+}
+
+// Marshal a Request appended to the provided destination slice as minified
+// JSON.
+func (en *Request) Marshal(dst []byte) (b []byte) {
+	var err error
+	b = dst
+	b = envelopes.Marshal(
+		b, L,
+		func(bst []byte) (o []byte) {
+			o = bst
+			o = append(o, '"')
+			o = append(o, en.Subscription...)
+			o = append(o, '"')
+			o = append(o, ',')
+			for _, f := range en.Filters {
+				o = append(o, ',')
+				o = f.Marshal(o)
+			}
+			return
+		},
+	)
+	_ = err
+	return
+}
+
+// Unmarshal a Request from minified JSON, returning the remainder after the end
+// of the envelope.
+func (en *Request) Unmarshal(b []byte) (r []byte, err error) {
+	r = b
+	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
+		return
+	}
+	if r, err = en.Filters.Unmarshal(r); chk.E(err) {
+		return
+	}
+	if r, err = envelopes.SkipToTheEnd(r); chk.E(err) {
+		return
+	}
+	return
+}
+
+// ParseRequest reads a Request in minified JSON into a newly allocated Request.
+func ParseRequest(b []byte) (t *Request, rem []byte, err error) {
+	t = New()
+	if rem, err = t.Unmarshal(b); chk.E(err) {
+		return
+	}
+	return
+}
+
+// Response is a COUNT Response returning a count and approximate flag
+// associated with the REQ subscription.Id.
+type Response struct {
+	Subscription []byte
+	Count        int
+	Approximate  bool
+}
+
+var _ codec.Envelope = (*Response)(nil)
+
+// NewResponse creates a new empty countenvelope.Response with a standard formatted
+// subscription.Id.
+func NewResponse() *Response { return new(Response) }
+
+// NewResponseFrom creates a new countenvelope.Response with provided string for the
+// subscription.Id, a count and optional variadic approximate flag, which is
+// otherwise false and does not get rendered into the JSON.
+func NewResponseFrom[V string | []byte](
+	s V, cnt int,
+	approx ...bool,
+) (res *Response, err error) {
+	var a bool
+	if len(approx) > 0 {
+		a = approx[0]
+	}
+	if len(s) < 0 || len(s) > 64 {
+		err = errorf.E("subscription id must be length > 0 and <= 64")
+		return
+	}
+	return &Response{[]byte(s), cnt, a}, nil
+}
+
+// Label returns the COUNT label associated with a Response.
+func (en *Response) Label() string { return L }
+
+// Write a Response to a provided io.Writer as minified JSON.
+func (en *Response) Write(w io.Writer) (err error) {
+	_, err = w.Write(en.Marshal(nil))
+	return
+}
+
+// Marshal a countenvelope.Response envelope in minified JSON, appending to a
+// provided destination slice.
+func (en *Response) Marshal(dst []byte) (b []byte) {
+	b = dst
+	b = envelopes.Marshal(
+		b, L,
+		func(bst []byte) (o []byte) {
+			o = bst
+			o = append(o, '"')
+			o = append(o, en.Subscription...)
+			o = append(o, '"')
+			o = append(o, ',')
+			c := ints.New(en.Count)
+			o = c.Marshal(o)
+			if en.Approximate {
+				o = append(o, ',')
+				o = append(o, "true"...)
+			}
+			return
+		},
+	)
+	return
+}
+
+// Unmarshal a COUNT Response from minified JSON, returning the remainder after
+// the end of the envelope.
+func (en *Response) Unmarshal(b []byte) (r []byte, err error) {
+	r = b
+	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
+		return
+	}
+	if r, err = text.Comma(r); chk.E(err) {
+		return
+	}
+	i := ints.New(0)
+	if r, err = i.Unmarshal(r); chk.E(err) {
+		return
+	}
+	en.Count = int(i.N)
+	if len(r) > 0 {
+		if r[0] == ',' {
+			r = r[1:]
+			if bytes.HasPrefix(r, []byte("true")) {
+				en.Approximate = true
+			}
+		}
+	}
+	if r, err = envelopes.SkipToTheEnd(r); chk.E(err) {
+		return
+	}
+	return
+}
+
+// Parse reads a Count Response in minified JSON into a newly allocated
+// countenvelope.Response.
+func Parse(b []byte) (t *Response, rem []byte, err error) {
+	t = NewResponse()
+	if rem, err = t.Unmarshal(b); chk.E(err) {
+		return
+	}
+	return
+}

pkg/encoders/envelopes/countenvelope/countenvelope_test.go

@@ -0,0 +1,135 @@
+package countenvelope
+
+import (
+	"testing"
+
+	"lol.mleku.dev/chk"
+	"lukechampine.com/frand"
+	"next.orly.dev/pkg/encoders/envelopes"
+	"next.orly.dev/pkg/encoders/filter"
+	"next.orly.dev/pkg/utils"
+	"next.orly.dev/pkg/utils/bufpool"
+)
+
+func TestRequest(t *testing.T) {
+	var err error
+	for i := range 1000 {
+		rb, rb1, rb2 := bufpool.Get(), bufpool.Get(), bufpool.Get()
+		var f filter.S
+		if f, err = filter.GenFilters(); chk.E(err) {
+			t.Fatal(err)
+		}
+		s := utils.NewSubscription(i)
+		req := NewRequest(s, f)
+		rb = req.Marshal(rb)
+		rb1 = append(rb1, rb...)
+		var rem []byte
+		var l string
+		if l, rb, err = envelopes.Identify(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if l != L {
+			t.Fatalf("invalid sentinel %s, expect %s", l, L)
+		}
+		req2 := New()
+		if rem, err = req2.Unmarshal(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if len(rem) > 0 {
+			t.Fatalf(
+				"unmarshal failed, remainder\n%d %s",
+				len(rem), rem,
+			)
+		}
+		rb2 = req2.Marshal(rb2)
+		if !utils.FastEqual(rb1, rb2) {
+			if len(rb1) != len(rb2) {
+				t.Fatalf(
+					"unmarshal failed, different lengths\n%d %s\n%d %s\n",
+					len(rb1), rb1, len(rb2), rb2,
+				)
+			}
+			for i := range rb1 {
+				if rb1[i] != rb2[i] {
+					t.Fatalf(
+						"unmarshal failed, difference at position %d\n%d %s\n%s\n%d %s\n%s\n",
+						i, len(rb1), rb1[:i], rb1[i:], len(rb2), rb2[:i],
+						rb2[i:],
+					)
+				}
+			}
+			t.Fatalf(
+				"unmarshal failed\n%d %s\n%d %s\n",
+				len(rb1), rb1, len(rb2), rb2,
+			)
+		}
+		bufpool.Put(rb1)
+		bufpool.Put(rb2)
+		bufpool.Put(rb)
+	}
+}
+
+func TestResponse(t *testing.T) {
+	var err error
+	for i := range 1000 {
+		rb, rb1, rb2 := bufpool.Get(), bufpool.Get(), bufpool.Get()
+		s := utils.NewSubscription(i)
+		var res *Response
+		if i&2 == 0 {
+			if res, err = NewResponseFrom(
+				s, frand.Intn(200), true,
+			); chk.E(err) {
+				t.Fatal(err)
+			}
+		} else {
+			if res, err = NewResponseFrom(s, frand.Intn(200)); chk.E(err) {
+				t.Fatal(err)
+			}
+		}
+		rb = res.Marshal(rb)
+		rb1 = append(rb1, rb...)
+		var rem []byte
+		var l string
+		if l, rb, err = envelopes.Identify(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if l != L {
+			t.Fatalf("invalid sentinel %s, expect %s", l, L)
+		}
+		res2 := NewResponse()
+		if rem, err = res2.Unmarshal(rb); chk.E(err) {
+			t.Fatal(err)
+		}
+		if len(rem) > 0 {
+			t.Fatalf(
+				"unmarshal failed, remainder\n%d %s",
+				len(rem), rem,
+			)
+		}
+		rb2 = res2.Marshal(rb2)
+		if !utils.FastEqual(rb1, rb2) {
+			if len(rb1) != len(rb2) {
+				t.Fatalf(
+					"unmarshal failed, different lengths\n%d %s\n%d %s\n",
+					len(rb1), rb1, len(rb2), rb2,
+				)
+			}
+			for i := range rb1 {
+				if rb1[i] != rb2[i] {
+					t.Fatalf(
+						"unmarshal failed, difference at position %d\n%d %s\n%s\n%d %s\n%s\n",
+						i, len(rb1), rb1[:i], rb1[i:], len(rb2), rb2[:i],
+						rb2[i:],
+					)
+				}
+			}
+			t.Fatalf(
+				"unmarshal failed\n%d %s\n%d %s\n",
+				len(rb1), rb1, len(rb2), rb2,
+			)
+		}
+		bufpool.Put(rb1)
+		bufpool.Put(rb2)
+		bufpool.Put(rb)
+	}
+}

pkg/encoders/envelopes/okenvelope/okenvelope.go

@@ -41,7 +41,7 @@ func NewFrom[V string | []byte](eid V, ok bool, msg ...V) *T {
 	}
 	if len(eid) != sha256.Size {
 		log.W.F(
-			"event ID unexpected length, expect %d got %d",
+			"event Subscription unexpected length, expect %d got %d",
 			len(eid), sha256.Size,
 		)
 	}
@@ -98,7 +98,7 @@ func (en *T) Unmarshal(b []byte) (r []byte, err error) {
 	}
 	if len(idBytes) != sha256.Size {
 		err = errorf.E(
-			"invalid size for ID, require %d got %d",
+			"invalid size for Subscription, require %d got %d",
 			sha256.Size, len(idBytes),
 		)
 		return

pkg/encoders/envelopes/reqenvelope/reqenvelope.go

@@ -87,7 +87,6 @@ func (en *T) Unmarshal(b []byte) (r []byte, err error) {
 	if en.Subscription, r, err = text.UnmarshalQuoted(r); chk.E(err) {
 		return
 	}
-
 	if r, err = text.Comma(r); chk.E(err) {
 		return
 	}

pkg/encoders/envelopes/reqenvelope/reqenvelope_test.go

@@ -7,14 +7,13 @@ import (
 	"next.orly.dev/pkg/encoders/envelopes"
 	"next.orly.dev/pkg/encoders/filter"
 	"next.orly.dev/pkg/utils"
+	"next.orly.dev/pkg/utils/bufpool"
 )
 
 func TestMarshalUnmarshal(t *testing.T) {
 	var err error
-	rb, rb1, rb2 := make([]byte, 0, 65535), make([]byte, 0, 65535), make(
-		[]byte, 0, 65535,
-	)
 	for i := range 1000 {
+		rb, rb1, rb2 := bufpool.Get(), bufpool.Get(), bufpool.Get()
 		var f filter.S
 		if f, err = filter.GenFilters(); chk.E(err) {
 			t.Fatal(err)
@@ -22,8 +21,7 @@ func TestMarshalUnmarshal(t *testing.T) {
 		s := utils.NewSubscription(i)
 		req := NewFrom(s, f)
 		rb = req.Marshal(rb)
-		rb1 = rb1[:len(rb)]
-		copy(rb1, rb)
+		rb1 = append(rb1, rb...)
 		var rem []byte
 		var l string
 		if l, rb, err = envelopes.Identify(rb); chk.E(err) {
@@ -64,6 +62,8 @@ func TestMarshalUnmarshal(t *testing.T) {
 				len(rb1), rb1, len(rb2), rb2,
 			)
 		}
-		rb, rb1, rb2 = rb[:0], rb1[:0], rb2[:0]
+		bufpool.Put(rb1)
+		bufpool.Put(rb2)
+		bufpool.Put(rb)
 	}
 }

pkg/encoders/event/event.go

@@ -297,7 +297,7 @@ InVal:
 		}
 		if len(id) != sha256.Size {
 			err = errorf.E(
-				"invalid ID, require %d got %d", sha256.Size,
+				"invalid Subscription, require %d got %d", sha256.Size,
 				len(id),
 			)
 			return

pkg/encoders/event/signatures.go

@@ -34,13 +34,13 @@ func (ev *E) Verify() (valid bool, err error) {
 		// check that this isn't because of a bogus ID
 		id := ev.GetIDBytes()
 		if !utils.FastEqual(id, ev.ID) {
-			log.E.Ln("event ID incorrect")
+			log.E.Ln("event Subscription incorrect")
 			ev.ID = id
 			err = nil
 			if valid, err = keys.Verify(ev.ID, ev.Sig); chk.E(err) {
 				return
 			}
-			err = errorf.W("event ID incorrect but signature is valid on correct ID")
+			err = errorf.W("event Subscription incorrect but signature is valid on correct Subscription")
 		}
 		return
 	}

pkg/encoders/filter/filter.go

@@ -237,7 +237,7 @@ const (
 //
 // todo: this may tolerate whitespace, not certain currently.
 func (f *F) Unmarshal(b []byte) (r []byte, err error) {
-	r = b[:]
+	r = b
 	var key []byte
 	var state int
 	for ; len(r) > 0; r = r[1:] {