Remove remaining traces of local_data

I've preserved is_local since it's still potentially useful.

Signed-off-by: Cole Miller <m@cole-miller.net>

src/leader.c

@@ -224,11 +224,7 @@ static void leaderMaybeCheckpointLegacy(struct leader *l)
 		tracef("raft_malloc - no mem");
 		goto err_after_buf_alloc;
 	}
-#ifdef USE_SYSTEM_RAFT
 	rv = raft_apply(l->raft, apply, &buf, 1, leaderCheckpointApplyCb);
-#else
-	rv = raft_apply(l->raft, apply, &buf, NULL, 1, leaderCheckpointApplyCb);
-#endif
 	if (rv != 0) {
 		tracef("raft_apply failed %d", rv);
 		raft_free(apply);
@@ -336,13 +332,7 @@ static int leaderApplyFrames(struct exec *req,
 	apply->type = COMMAND_FRAMES;
 	idSet(apply->req.req_id, req->id);
 
-#ifdef USE_SYSTEM_RAFT
 	rv = raft_apply(l->raft, &apply->req, &buf, 1, leaderApplyFramesCb);
-#else
-	/* TODO actual WAL slice goes here */
-	struct raft_entry_local_data local_data = {};
-	rv = raft_apply(l->raft, &apply->req, &buf, &local_data, 1, leaderApplyFramesCb);
-#endif
 	if (rv != 0) {
 		tracef("raft apply failed %d", rv);
 		goto err_after_command_encode;

src/raft.h

@@ -198,28 +198,6 @@ enum {
 	RAFT_CHANGE       /* Raft configuration change. */
 };
 
-/**
- * A small fixed-size inline buffer that stores extra data for a raft_entry
- * that is different for each node in the cluster.
- *
- * A leader initializes the local data for an entry before passing it into
- * raft_apply. This local data is stored in the volatile raft log and also
- * in the persistent raft log on the leader. AppendEntries messages sent by
- * the leader never contain the local data for entries.
- *
- * When a follower accepts an AppendEntries request, it invokes a callback
- * provided by the FSM to fill out the local data for each new entry before
- * appending the entries to its log (volatile and persistent). This local
- * data doesn't have to be the same as the local data that the leader computed.
- *
- * When starting up, a raft node reads the local data for each entry for its
- * persistent log as part of populating the volatile log.
- */
-struct raft_entry_local_data {
-	/* Must be the only member of this struct. */
-	uint8_t buf[16];
-};
-
 /**
  * A single entry in the raft log.
  *
@@ -250,20 +228,13 @@ struct raft_entry_local_data {
  * message or in the persistent log. This field can be used by the FSM's `apply`
  * callback to handle a COMMAND entry differently depending on whether it
  * originated locally.
- *
- * Note: The @local_data and @is_local fields do not exist when we use an external
- * libraft, because the last separate release of libraft predates their addition.
- * The ifdef at the very top of this file ensures that we use the system raft headers
- * when we build against an external libraft, so there will be no ABI mismatch as
- * a result of incompatible struct layouts.
  */
 struct raft_entry
 {
 	raft_term term;         /* Term in which the entry was created. */
 	unsigned short type;    /* Type (FSM command, barrier, config change). */
 	bool is_local;          /* Placed here so it goes in the padding after @type. */
 	struct raft_buffer buf; /* Entry data. */
-	struct raft_entry_local_data local_data;
 	void *batch;            /* Batch that buf's memory points to, if any. */
 };
 
@@ -1244,7 +1215,6 @@ struct raft_apply
 RAFT_API int raft_apply(struct raft *r,
 			struct raft_apply *req,
 			const struct raft_buffer bufs[],
-			const struct raft_entry_local_data local_data[],
 			const unsigned n,
 			raft_apply_cb cb);
 

src/raft/client.c

@@ -14,7 +14,6 @@
 int raft_apply(struct raft *r,
 	       struct raft_apply *req,
 	       const struct raft_buffer bufs[],
-	       const struct raft_entry_local_data local_data[],
 	       const unsigned n,
 	       raft_apply_cb cb)
 {
@@ -42,7 +41,7 @@ int raft_apply(struct raft *r,
 	req->cb = cb;
 
 	/* Append the new entries to the log. */
-	rv = logAppendCommands(r->log, r->current_term, bufs, local_data, n);
+	rv = logAppendCommands(r->log, r->current_term, bufs, n);
 	if (rv != 0) {
 		goto err;
 	}
@@ -91,7 +90,7 @@ int raft_barrier(struct raft *r, struct raft_barrier *req, raft_barrier_cb cb)
 	req->index = index;
 	req->cb = cb;
 
-	rv = logAppend(r->log, r->current_term, RAFT_BARRIER, buf, (struct raft_entry_local_data){}, true, NULL);
+	rv = logAppend(r->log, r->current_term, RAFT_BARRIER, buf, true, NULL);
 	if (rv != 0) {
 		goto err_after_buf_alloc;
 	}

src/raft/fixture.c

@@ -1317,7 +1317,7 @@ static void copyLeaderLog(struct raft_fixture *f)
 		assert(buf.base != NULL);
 		memcpy(buf.base, entry->buf.base, buf.len);
 		/* FIXME(cole) what to do here for is_local? */
-		rv = logAppend(f->log, entry->term, entry->type, buf, (struct raft_entry_local_data){}, false, NULL);
+		rv = logAppend(f->log, entry->term, entry->type, buf, false, NULL);
 		assert(rv == 0);
 	}
 	logRelease(raft->log, 1, entries, n);

src/raft/log.c

@@ -546,7 +546,6 @@ int logAppend(struct raft_log *l,
 	      const raft_term term,
 	      const unsigned short type,
 	      struct raft_buffer buf,
-	      struct raft_entry_local_data local_data,
 	      bool is_local,
 	      void *batch)
 {
@@ -576,7 +575,6 @@ int logAppend(struct raft_log *l,
 	entry->type = type;
 	entry->buf = buf;
 	entry->batch = batch;
-	entry->local_data = local_data;
 	entry->is_local = is_local;
 
 	l->back += 1;
@@ -588,7 +586,6 @@ int logAppend(struct raft_log *l,
 int logAppendCommands(struct raft_log *l,
 		      const raft_term term,
 		      const struct raft_buffer bufs[],
-		      const struct raft_entry_local_data local_data[],
 		      const unsigned n)
 {
 	unsigned i;
@@ -600,8 +597,7 @@ int logAppendCommands(struct raft_log *l,
 	assert(n > 0);
 
 	for (i = 0; i < n; i++) {
-		struct raft_entry_local_data loc = (local_data != NULL) ? local_data[i] : (struct raft_entry_local_data){};
-		rv = logAppend(l, term, RAFT_COMMAND, bufs[i], loc, true, NULL);
+		rv = logAppend(l, term, RAFT_COMMAND, bufs[i], true, NULL);
 		if (rv != 0) {
 			return rv;
 		}
@@ -628,7 +624,7 @@ int logAppendConfiguration(struct raft_log *l,
 	}
 
 	/* Append the new entry to the log. */
-	rv = logAppend(l, term, RAFT_CHANGE, buf, (struct raft_entry_local_data){}, true, NULL);
+	rv = logAppend(l, term, RAFT_CHANGE, buf, true, NULL);
 	if (rv != 0) {
 		goto err_after_encode;
 	}

src/raft/log.h

@@ -114,15 +114,13 @@ int logAppend(struct raft_log *l,
 	      raft_term term,
 	      unsigned short type,
 	      struct raft_buffer buf,
-	      struct raft_entry_local_data local_data,
 	      bool is_local,
 	      void *batch);
 
 /* Convenience to append a series of #RAFT_COMMAND entries. */
 int logAppendCommands(struct raft_log *l,
 		      const raft_term term,
 		      const struct raft_buffer bufs[],
-		      const struct raft_entry_local_data local_data[],
 		      const unsigned n);
 
 /* Convenience to encode and append a single #RAFT_CHANGE entry. */

src/raft/replication.c

@@ -1235,7 +1235,7 @@ int replicationAppend(struct raft *r,
 			goto err_after_request_alloc;
 		}
 
-		rv = logAppend(r->log, copy.term, copy.type, copy.buf, (struct raft_entry_local_data){}, false, NULL);
+		rv = logAppend(r->log, copy.term, copy.type, copy.buf, false, NULL);
 		if (rv != 0) {
 			goto err_after_request_alloc;
 		}

src/raft/start.c

@@ -72,7 +72,7 @@ static int restoreEntries(struct raft *r,
 	for (i = 0; i < n; i++) {
 		struct raft_entry *entry = &entries[i];
 		rv = logAppend(r->log, entry->term, entry->type, entry->buf,
-			       entry->local_data, entry->is_local, entry->batch);
+			       entry->is_local, entry->batch);
 		if (rv != 0) {
 			goto err;
 		}

src/raft/uv_append.c

@@ -597,7 +597,7 @@ static size_t uvAppendSize(struct uvAppend *a)
 {
 	size_t size = sizeof(uint32_t) * 2; /* CRC checksums */
 	unsigned i;
-	size += uvSizeofBatchHeader(a->n, true); /* Batch header */
+	size += uvSizeofBatchHeader(a->n); /* Batch header */
 	for (i = 0; i < a->n; i++) {       /* Entries data */
 		size += bytePad64(a->entries[i].buf.len);
 	}

src/raft/uv_encoding.c

@@ -86,11 +86,10 @@ static size_t sizeofTimeoutNow(void)
 	       sizeof(uint64_t) /* Last log term. */;
 }
 
-size_t uvSizeofBatchHeader(size_t n, bool with_local_data)
+size_t uvSizeofBatchHeader(size_t n)
 {
 	size_t res = 8 + /* Number of entries in the batch, little endian */
 		16 * n; /* One header per entry */;
-	(void)with_local_data;
 	return res;
 }
 
@@ -139,7 +138,7 @@ static void encodeAppendEntries(const struct raft_append_entries *p, void *buf)
 	bytePut64(&cursor, p->prev_log_term);  /* Previous term. */
 	bytePut64(&cursor, p->leader_commit);  /* Commit index. */
 
-	uvEncodeBatchHeader(p->entries, p->n_entries, cursor, false /* no local data */);
+	uvEncodeBatchHeader(p->entries, p->n_entries, cursor);
 }
 
 static void encodeAppendEntriesResult(
@@ -297,17 +296,14 @@ int uvEncodeMessage(const struct raft_message *message,
 
 void uvEncodeBatchHeader(const struct raft_entry *entries,
 			 unsigned n,
-			 void *buf,
-			 bool with_local_data)
+			 void *buf)
 {
 	unsigned i;
 	void *cursor = buf;
 
 	/* Number of entries in the batch, little endian */
 	bytePut64(&cursor, n);
 
-	(void)with_local_data;
-
 	for (i = 0; i < n; i++) {
 		const struct raft_entry *entry = &entries[i];
 
@@ -368,8 +364,7 @@ static void decodeRequestVoteResult(const uv_buf_t *buf,
 
 int uvDecodeBatchHeader(const void *batch,
 			struct raft_entry **entries,
-			unsigned *n,
-			uint64_t *local_data_size)
+			unsigned *n)
 {
 	const void *cursor = batch;
 	size_t i;
@@ -382,8 +377,6 @@ int uvDecodeBatchHeader(const void *batch,
 		return 0;
 	}
 
-	(void)local_data_size;
-
 	*entries = raft_malloc(*n * sizeof **entries);
 
 	if (*entries == NULL) {
@@ -438,7 +431,7 @@ static int decodeAppendEntries(const uv_buf_t *buf,
 	args->prev_log_term = byteGet64(&cursor);
 	args->leader_commit = byteGet64(&cursor);
 
-	rv = uvDecodeBatchHeader(cursor, &args->entries, &args->n_entries, false);
+	rv = uvDecodeBatchHeader(cursor, &args->entries, &args->n_entries);
 	if (rv != 0) {
 		return rv;
 	}
@@ -560,8 +553,7 @@ int uvDecodeMessage(uint16_t type,
 int uvDecodeEntriesBatch(uint8_t *batch,
 			 size_t offset,
 			 struct raft_entry *entries,
-			 unsigned n,
-			 uint64_t local_data_size)
+			 unsigned n)
 {
 	uint8_t *cursor;
 
@@ -581,10 +573,6 @@ int uvDecodeEntriesBatch(uint8_t *batch,
 		}
 
 		entry->is_local = false;
-
-		entry->local_data = (struct raft_entry_local_data){};
-		assert(local_data_size <= sizeof(entry->local_data.buf));
-		assert(local_data_size % 8 == 0);
 	}
 	return 0;
 }

src/raft/uv_encoding.h

@@ -21,14 +21,12 @@ int uvDecodeMessage(uint16_t type,
 
 int uvDecodeBatchHeader(const void *batch,
 			struct raft_entry **entries,
-			unsigned *n,
-			uint64_t *local_data_size);
+			unsigned *n);
 
 int uvDecodeEntriesBatch(uint8_t *batch,
 			 size_t offset,
 			 struct raft_entry *entries,
-			 unsigned n,
-			 uint64_t local_data_size);
+			 unsigned n);
 
 /**
  * The layout of the memory pointed at by a @batch pointer is the following:
@@ -47,17 +45,15 @@ int uvDecodeEntriesBatch(uint8_t *batch,
  * [1 byte ] Message type (Either RAFT_COMMAND or RAFT_CHANGE)
  * [3 bytes] Currently unused.
  * [4 bytes] Size of the log entry data, little endian.
- * [8 bytes] Size of the local buffer, little endian.
  *
  * A payload data section for an entry is simply a sequence of bytes of
  * arbitrary lengths, possibly padded with extra bytes to reach 8-byte boundary
  * (which means that all entry data pointers are 8-byte aligned).
  */
-size_t uvSizeofBatchHeader(size_t n, bool with_local_data);
+size_t uvSizeofBatchHeader(size_t n);
 
 void uvEncodeBatchHeader(const struct raft_entry *entries,
 			 unsigned n,
-			 void *buf,
-			 bool with_local_data);
+			 void *buf);
 
 #endif /* UV_ENCODING_H_ */

src/raft/uv_recv.c

@@ -294,8 +294,7 @@ static void uvServerReadCb(uv_stream_t *stream,
 					    payload.base, 0,
 					    s->message.append_entries.entries,
 					    s->message.append_entries
-						.n_entries,
-					    false);
+						.n_entries);
 					break;
 				case RAFT_IO_INSTALL_SNAPSHOT:
 					s->message.install_snapshot.data.base =