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Migrate OnchainEvent serialization to be MaybeReadable.
This adds a new TLV-based enum serialization macro entitled `impl_writeable_tlv_based_enum_upgradable`. As the name implies, the new macro allows us to ignore odd-numbered variant entries. Because the new macro implements only `MaybeReadable` and not `Readable`, it is not applicable in many contexts, here only being added for the two `OnchainEvent` structs.
1 parent 9efaf66 commit 97ef299

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3 files changed

+144
-32
lines changed

3 files changed

+144
-32
lines changed

lightning/src/chain/channelmonitor.rs

+38-11
Original file line numberDiff line numberDiff line change
@@ -106,7 +106,9 @@ impl Readable for ChannelMonitorUpdate {
106106
let len: u64 = Readable::read(r)?;
107107
let mut updates = Vec::with_capacity(cmp::min(len as usize, MAX_ALLOC_SIZE / ::core::mem::size_of::<ChannelMonitorUpdateStep>()));
108108
for _ in 0..len {
109-
updates.push(Readable::read(r)?);
109+
if let Some(upd) = MaybeReadable::read(r)? {
110+
updates.push(upd);
111+
}
110112
}
111113
read_tlv_fields!(r, {});
112114
Ok(Self { update_id, updates })
@@ -394,13 +396,36 @@ enum OnchainEvent {
394396
},
395397
}
396398

397-
impl_writeable_tlv_based!(OnchainEventEntry, {
398-
(0, txid, required),
399-
(2, height, required),
400-
(4, event, required),
401-
});
399+
impl Writeable for OnchainEventEntry {
400+
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
401+
write_tlv_fields!(writer, {
402+
(0, self.txid, required),
403+
(2, self.height, required),
404+
(4, self.event, required),
405+
});
406+
Ok(())
407+
}
408+
}
402409

403-
impl_writeable_tlv_based_enum!(OnchainEvent,
410+
impl MaybeReadable for OnchainEventEntry {
411+
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
412+
let mut txid = Default::default();
413+
let mut height = 0;
414+
let mut event = None;
415+
read_tlv_fields!(reader, {
416+
(0, txid, required),
417+
(2, height, required),
418+
(4, event, maybe_readable),
419+
});
420+
if let Some(ev) = event {
421+
Ok(Some(Self { txid, height, event: ev }))
422+
} else {
423+
Ok(None)
424+
}
425+
}
426+
}
427+
428+
impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
404429
(0, HTLCUpdate) => {
405430
(0, source, required),
406431
(1, onchain_value_satoshis, option),
@@ -409,7 +434,7 @@ impl_writeable_tlv_based_enum!(OnchainEvent,
409434
(1, MaturingOutput) => {
410435
(0, descriptor, required),
411436
},
412-
;);
437+
);
413438

414439
#[cfg_attr(any(test, feature = "fuzztarget", feature = "_test_utils"), derive(PartialEq))]
415440
#[derive(Clone)]
@@ -443,7 +468,7 @@ pub(crate) enum ChannelMonitorUpdateStep {
443468
},
444469
}
445470

446-
impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep,
471+
impl_writeable_tlv_based_enum_upgradable!(ChannelMonitorUpdateStep,
447472
(0, LatestHolderCommitmentTXInfo) => {
448473
(0, commitment_tx, required),
449474
(2, htlc_outputs, vec_type),
@@ -467,7 +492,7 @@ impl_writeable_tlv_based_enum!(ChannelMonitorUpdateStep,
467492
(5, ShutdownScript) => {
468493
(0, scriptpubkey, required),
469494
},
470-
;);
495+
);
471496

472497
/// A ChannelMonitor handles chain events (blocks connected and disconnected) and generates
473498
/// on-chain transactions to ensure no loss of funds occurs.
@@ -2731,7 +2756,9 @@ impl<'a, Signer: Sign, K: KeysInterface<Signer = Signer>> ReadableArgs<&'a K>
27312756
let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
27322757
let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
27332758
for _ in 0..waiting_threshold_conf_len {
2734-
onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?);
2759+
if let Some(val) = MaybeReadable::read(reader)? {
2760+
onchain_events_awaiting_threshold_conf.push(val);
2761+
}
27352762
}
27362763

27372764
let outputs_to_watch_len: u64 = Readable::read(reader)?;

lightning/src/chain/onchaintx.rs

+34-9
Original file line numberDiff line numberDiff line change
@@ -29,7 +29,7 @@ use chain::channelmonitor::{ANTI_REORG_DELAY, CLTV_SHARED_CLAIM_BUFFER};
2929
use chain::keysinterface::{Sign, KeysInterface};
3030
use chain::package::PackageTemplate;
3131
use util::logger::Logger;
32-
use util::ser::{Readable, ReadableArgs, Writer, Writeable, VecWriter};
32+
use util::ser::{Readable, ReadableArgs, MaybeReadable, Writer, Writeable, VecWriter};
3333
use util::byte_utils;
3434

3535
use io;
@@ -79,20 +79,43 @@ enum OnchainEvent {
7979
}
8080
}
8181

82-
impl_writeable_tlv_based!(OnchainEventEntry, {
83-
(0, txid, required),
84-
(2, height, required),
85-
(4, event, required),
86-
});
82+
impl Writeable for OnchainEventEntry {
83+
fn write<W: Writer>(&self, writer: &mut W) -> Result<(), ::std::io::Error> {
84+
write_tlv_fields!(writer, {
85+
(0, self.txid, required),
86+
(2, self.height, required),
87+
(4, self.event, required),
88+
});
89+
Ok(())
90+
}
91+
}
8792

88-
impl_writeable_tlv_based_enum!(OnchainEvent,
93+
impl MaybeReadable for OnchainEventEntry {
94+
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, DecodeError> {
95+
let mut txid = Default::default();
96+
let mut height = 0;
97+
let mut event = None;
98+
read_tlv_fields!(reader, {
99+
(0, txid, required),
100+
(2, height, required),
101+
(4, event, maybe_readable),
102+
});
103+
if let Some(ev) = event {
104+
Ok(Some(Self { txid, height, event: ev }))
105+
} else {
106+
Ok(None)
107+
}
108+
}
109+
}
110+
111+
impl_writeable_tlv_based_enum_upgradable!(OnchainEvent,
89112
(0, Claim) => {
90113
(0, claim_request, required),
91114
},
92115
(1, ContentiousOutpoint) => {
93116
(0, package, required),
94117
},
95-
;);
118+
);
96119

97120
impl Readable for Option<Vec<Option<(usize, Signature)>>> {
98121
fn read<R: io::Read>(reader: &mut R) -> Result<Self, DecodeError> {
@@ -296,7 +319,9 @@ impl<'a, K: KeysInterface> ReadableArgs<&'a K> for OnchainTxHandler<K::Signer> {
296319
let waiting_threshold_conf_len: u64 = Readable::read(reader)?;
297320
let mut onchain_events_awaiting_threshold_conf = Vec::with_capacity(cmp::min(waiting_threshold_conf_len as usize, MAX_ALLOC_SIZE / 128));
298321
for _ in 0..waiting_threshold_conf_len {
299-
onchain_events_awaiting_threshold_conf.push(Readable::read(reader)?);
322+
if let Some(val) = MaybeReadable::read(reader)? {
323+
onchain_events_awaiting_threshold_conf.push(val);
324+
}
300325
}
301326

302327
read_tlv_fields!(reader, {});

lightning/src/util/ser_macros.rs

+72-12
Original file line numberDiff line numberDiff line change
@@ -115,6 +115,9 @@ macro_rules! check_tlv_order {
115115
($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, vec_type) => {{
116116
// no-op
117117
}};
118+
($last_seen_type: expr, $typ: expr, $type: expr, $field: ident, maybe_readable) => {{
119+
// no-op
120+
}};
118121
}
119122

120123
macro_rules! check_missing_tlv {
@@ -138,6 +141,9 @@ macro_rules! check_missing_tlv {
138141
($last_seen_type: expr, $type: expr, $field: ident, option) => {{
139142
// no-op
140143
}};
144+
($last_seen_type: expr, $type: expr, $field: ident, maybe_readable) => {{
145+
// no-op
146+
}};
141147
}
142148

143149
macro_rules! decode_tlv {
@@ -153,6 +159,9 @@ macro_rules! decode_tlv {
153159
($reader: expr, $field: ident, option) => {{
154160
$field = Some(ser::Readable::read(&mut $reader)?);
155161
}};
162+
($reader: expr, $field: ident, maybe_readable) => {{
163+
$field = ser::MaybeReadable::read(&mut $reader)?;
164+
}};
156165
}
157166

158167
macro_rules! decode_tlv_stream {
@@ -405,7 +414,7 @@ macro_rules! init_tlv_field_var {
405414
};
406415
($field: ident, option) => {
407416
let mut $field = None;
408-
}
417+
};
409418
}
410419

411420
/// Implements Readable/Writeable for a struct storing it as a set of TLVs
@@ -458,17 +467,7 @@ macro_rules! impl_writeable_tlv_based {
458467
}
459468
}
460469

461-
/// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple
462-
/// variants stored directly.
463-
/// The format is, for example
464-
/// impl_writeable_tlv_based_enum!(EnumName,
465-
/// (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
466-
/// (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
467-
/// (2, TupleVariantA), (3, TupleVariantB),
468-
/// );
469-
/// The type is written as a single byte, followed by any variant data.
470-
/// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature.
471-
macro_rules! impl_writeable_tlv_based_enum {
470+
macro_rules! _impl_writeable_tlv_based_enum_common {
472471
($st: ident, $(($variant_id: expr, $variant_name: ident) =>
473472
{$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
474473
),* $(,)*;
@@ -492,6 +491,67 @@ macro_rules! impl_writeable_tlv_based_enum {
492491
Ok(())
493492
}
494493
}
494+
}
495+
}
496+
497+
/// Implement MaybeReadable and Writeable for an enum, with struct variants stored as TLVs and
498+
/// tuple variants stored directly.
499+
macro_rules! impl_writeable_tlv_based_enum_upgradable {
500+
($st: ident, $(($variant_id: expr, $variant_name: ident) =>
501+
{$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
502+
),* $(,)*) => {
503+
_impl_writeable_tlv_based_enum_common!($st,
504+
$(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*; );
505+
506+
impl ::util::ser::MaybeReadable for $st {
507+
fn read<R: ::std::io::Read>(reader: &mut R) -> Result<Option<Self>, ::ln::msgs::DecodeError> {
508+
let id: u8 = ::util::ser::Readable::read(reader)?;
509+
match id {
510+
$($variant_id => {
511+
// Because read_tlv_fields creates a labeled loop, we cannot call it twice
512+
// in the same function body. Instead, we define a closure and call it.
513+
let f = || {
514+
$(
515+
init_tlv_field_var!($field, $fieldty);
516+
)*
517+
read_tlv_fields!(reader, {
518+
$(($type, $field, $fieldty)),*
519+
});
520+
Ok(Some($st::$variant_name {
521+
$(
522+
$field: init_tlv_based_struct_field!($field, $fieldty)
523+
),*
524+
}))
525+
};
526+
f()
527+
}),*
528+
_ if id % 2 == 1 => { Ok(None) }
529+
_ => { Err(DecodeError::UnknownRequiredFeature)? },
530+
}
531+
}
532+
}
533+
534+
}
535+
}
536+
537+
/// Implement Readable and Writeable for an enum, with struct variants stored as TLVs and tuple
538+
/// variants stored directly.
539+
/// The format is, for example
540+
/// impl_writeable_tlv_based_enum!(EnumName,
541+
/// (0, StructVariantA) => {(0, required_variant_field, required), (1, optional_variant_field, option)},
542+
/// (1, StructVariantB) => {(0, variant_field_a, required), (1, variant_field_b, required), (2, variant_vec_field, vec_type)};
543+
/// (2, TupleVariantA), (3, TupleVariantB),
544+
/// );
545+
/// The type is written as a single byte, followed by any variant data.
546+
/// Attempts to read an unknown type byte result in DecodeError::UnknownRequiredFeature.
547+
macro_rules! impl_writeable_tlv_based_enum {
548+
($st: ident, $(($variant_id: expr, $variant_name: ident) =>
549+
{$(($type: expr, $field: ident, $fieldty: tt)),* $(,)*}
550+
),* $(,)*;
551+
$(($tuple_variant_id: expr, $tuple_variant_name: ident)),* $(,)*) => {
552+
_impl_writeable_tlv_based_enum_common!($st,
553+
$(($variant_id, $variant_name) => {$(($type, $field, $fieldty)),*}),*;
554+
$(($tuple_variant_id, $tuple_variant_name)),*);
495555

496556
impl ::util::ser::Readable for $st {
497557
fn read<R: $crate::io::Read>(reader: &mut R) -> Result<Self, ::ln::msgs::DecodeError> {

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