* lib/protocol: Require at least 3.125% savings from compression
The new lz4 library doesn't need its output buffer to be the maximum
size, unlike the old one (which would allocate if it weren't). It can
take a buffer that is of a smaller size and will report if compressed
data can fit inside the buffer (with a small chance of reporting a false
negative). Use that property to our advantage by requiring compressed
data to be at most n-n/32 = .96875*n bytes long for n input bytes.
* lib/protocol: Remove unused receivers
To make DeepSource happy.
* lib/protocol: Micro-optimize lz4Compress
Only write the length if compression was successful. This is a memory
write, so the compiler can't reorder it.
Only check the return value of lz4.CompressBlock. Length-zero inputs
are always expanded by LZ4 compression (the library documents this),
so the check on len(src) isn't needed.
We incorrectly gave a too small buffer to lz4.Compress, causing it to
allocate in some cases (when the data actually becomes larger when
compressed). This then panicked when passed to the buffer pool.
This ensures a buffer that is large enough, and adds tripwires closer to
the source in case this ever pops up again. There is a test that
exercises the issue.
This constructs the map of hashes of zero blocks from constants instead
of calculating it at startup time. A new test verifies that the map is
correct.
This avoids waiting until next ping and timeout until the connection is actually
closed both by notifying the peer of the disconnect and by immediately closing
the local end of the connection after that. As a nice side effect, info level
logging about dropped connections now have the actual reason in it, not a generic
timeout error which looks like a real problem with the connection.
Adds a receive only folder type that does not send changes, and where the user can optionally revert local changes. Also changes some of the icons to make the three folder types distinguishable.
We have the invalid bit to indicate that a file isn't good. That's enough for remote devices. For ourselves, it would be good to know sometimes why the file isn't good - because it's an unsupported type, because it matches an ignore pattern, or because we detected the data is bad and we need to rescan it.
Or, and this is the main future reason for the PR, because it's a change detected on a receive only device. We will want something like the invalid flag for those changes, but marking them as invalid today means the scanner will rehash them. Hence something more fine grained is required.
This introduces a LocalFlags fields to the FileInfo where we can stash things that we care about locally. For example,
FlagLocalUnsupported = 1 << 0 // The kind is unsupported, e.g. symlinks on Windows
FlagLocalIgnored = 1 << 1 // Matches local ignore patterns
FlagLocalMustRescan = 1 << 2 // Doesn't match content on disk, must be rechecked fully
The LocalFlags fields isn't sent over the wire; instead the Invalid attribute is calculated based on the flags at index sending time. It's on the FileInfo anyway because that's what we serialize to database etc.
The actual Invalid flag should after this just be considered when building the global state and figuring out availability for remote devices. It is not used for local file index entries.
When scanner.Walk detects a change, it now returns the new file info as well as the old file info. It also finds deleted and ignored files while scanning.
Also directory deletions are now always committed to db after their children to prevent temporary failure on remote due to non-empty directory.
The protobuf encoder now produces packed arrays for things like []int32,
which is actually correct according to the proto3 spec. However
Syncthing v0.14.16 and earlier doesn't support this. This reverts the
encoding change, but keeps the updated decoder so that we are both more
compatible with other proto3 implementations and can move to the updated
encoder in the future.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3856
This adds a new nanoseconds field to the FileInfo, populates it during
scans and sets the non-truncated time in Chtimes calls.
The actual file modification time is defined as modified_s seconds +
modified_ns nanoseconds. It's expected that the modified_ns field is <=
1e9 (that is, all whole seconds should go in the modified_s field) but
not really enforced. Given that it's an int32 the timestamp can be
adjusted += ~2.9 seconds by the modified_ns field...
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3431
This changes the BEP protocol to use protocol buffer serialization
instead of XDR, and therefore also the database format. The local
discovery protocol is also updated to be protocol buffer format.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3276
LGTM: AudriusButkevicius
This is in preparation for future changes, but also improves the
handling when talking to pre-v0.13 clients. It breaks out the Hello
message and magic from the rest of the protocol implementation, with the
intention that this small part of the protocol will survive future
changes.
To enable this, and future testing, the new ExchangeHello function takes
an interface that can be implemented by future Hello versions and
returns a version indendent result type. It correctly detects pre-v0.13
protocols and returns a "too old" error message which gets logged to the
user at warning level:
[I6KAH] 09:21:36 WARNING: Connecting to [...]:
the remote device speaks an older version of the protocol (v0.12) not
compatible with this version
Conversely, something entirely unknown will generate:
[I6KAH] 09:40:27 WARNING: Connecting to [...]:
the remote device speaks an unknown (newer?) version of the protocol
The intention is that in future iterations the Hello exchange will
succeed on at least one side and ExchangeHello will return the actual
data from the Hello together with ErrTooOld and an even more precise
message can be generated.
GitHub-Pull-Request: https://github.com/syncthing/syncthing/pull/3289
