b22b29679b
* Pre: remove remnants of 'open_empty' * Pre: Cleanup 'datoms' table after a timeline move Since timeline move operations use a transactor, they generate a "phantom" 'tx' and a 'txInstant' assertion. It is "phantom" in a sense that it was never present in the 'transactions' table, and is entirely synthetic as far as our database is concerned. It's an implementational artifact, and we were not cleaning it up. It becomes a problem when we start inserting transactions after a move. Once the transactor clashes with the phantom 'tx', it will retract the phantom 'txInstant' value, leaving the transactions log in an incorrect state. This patch adds a test for this scenario and elects the easy way out: simply remove the offending 'txInstant' datom. * Part 1: Sync without support for side-effects A "side-effect" is defined here as a mutation of a remote state as part of the sync. If, during a sync we determine that a remote state needs to be changed, bail out. This generally supports different variations of "baton-passing" syncing, where clients will succeed syncing if each change is non-conflicting. * Part 2: Support basic "side-effects" syncing This patch introduces a concept of a follow-up sync. If a sync generated a "merge transaction" (a regular transaction that contains assertions necessary for local and remote transaction logs to converge), then this transaction needs to be uploaded in a follow-up sync. Generated SyncReport indicates if a follow-up sync is required. Follow-up sync itself is just a regular sync. If remote state did not change, it will result in a simple RemoteFastForward. Otherwise, we'll continue merging and requesting a follow-up. Schema alterations are explicitly not supported. As local transactions are rebased on top of remote, following changes happen: - entids are changed into tempids, letting transactor upsert :db/unique values - entids for retractions are changed into lookup-refs if we're confident they'll succeed -- otherwise, retractions are dropped on the floor * Post: use a macro for more readable tests * Tolstoy README
33 lines
1.4 KiB
Rust
33 lines
1.4 KiB
Rust
// Copyright 2018 Mozilla
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//
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
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// this file except in compliance with the License. You may obtain a copy of the
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// License at http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed
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// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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// CONDITIONS OF ANY KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations under the License.
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// TODO: use `log` crate.
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// TODO it would be nice to be able to pass
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// in a logger into Syncer::flow; would allow for a "debug mode"
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// and getting useful logs out of clients.
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// See https://github.com/mozilla/mentat/issues/571
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// Below is some debug Android-friendly logging:
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// use std::os::raw::c_char;
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// use std::os::raw::c_int;
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// use std::ffi::CString;
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// pub const ANDROID_LOG_DEBUG: i32 = 3;
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// extern { pub fn __android_log_write(prio: c_int, tag: *const c_char, text: *const c_char) -> c_int; }
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pub fn d(message: &str) {
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println!("d: {}", message);
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// let message = CString::new(message).unwrap();
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// let message = message.as_ptr();
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// let tag = CString::new("RustyToodle").unwrap();
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// let tag = tag.as_ptr();
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// unsafe { __android_log_write(ANDROID_LOG_DEBUG, tag, message) };
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}
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