Merge pull request #1932 from holochain/fallback-build-validation-pac…

…kages-dht-with-smart-validation

Add ability to validate entries with full chain validation when author is offline

CHANGELOG-UNRELEASED.md

@@ -6,8 +6,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 
 ### Added
 
-- Adds smarter ordering of pending validation. Builds a dependency graph and only will try to validate entries that do not have dependencies also awaiting validation as this will always fail. [#1924](https://github.com/holochain/holochain-rust/pull/1924)
 - Adds support for [hApp-bundles](https://github.com/holochain/holoscape/tree/master/example-bundles) to `hc run`. This enables complex hApp setups with multiple DNAs and bridges to be easily run during development without having to write/maintain a conductor config file. [#1939](https://github.com/holochain/holochain-rust/pull/1939)
+- Adds ability to validate entries with full chain validation when author is offline [#1932](https://github.com/holochain/holochain-rust/pull/1932)
 
 ### Changed
 

app_spec/test/files/offline-validation.js

@@ -0,0 +1,101 @@
+const { one } = require('../config')
+
+const delay = ms => new Promise(resolve => setTimeout(resolve, ms)) 
+
+module.exports = scenario => {
+
+      scenario('Can retrieve header entries using get_entry', async (s, t) => {
+        const { alice, bob } = await s.players({ alice: one, bob: one })
+        await alice.spawn()
+        await bob.spawn()
+
+        await s.consistency()
+
+        // alice publishes a memo. This is private but should still publish a header
+        const create_result = await alice.call('app', "blog", "create_memo", { content: "private memo" })
+        t.comment(JSON.stringify(create_result))
+        t.equal(create_result.Ok.length, 46)
+        await s.consistency()
+
+        // get all the chain header hashes and check if they are retrievable
+        const maybe_chain_header_hashes = await alice.call('app', "blog", "get_chain_header_hashes", {})
+        t.ok(maybe_chain_header_hashes.Ok)
+        let chain_header_hashes = maybe_chain_header_hashes.Ok
+        t.equal(chain_header_hashes.length, 4) // dna, agentId, cap grant, memo
+
+        t.comment(JSON.stringify(chain_header_hashes))
+        let chain_headers = []
+
+        await s.consistency()
+
+        for (let i=0; i< chain_header_hashes.length; i++) {
+            // can use get_post because it just returns a raw entry given a hash
+            let header_hash = chain_header_hashes[i]
+            t.comment(header_hash)
+
+            // check bob can retrieve alices header entries
+            let header_bob = await bob.call('app', "blog", "get_post", { post_address: header_hash })
+            t.ok(header_bob.Ok)
+
+            chain_headers.push(header_bob.Ok)
+        }
+        t.comment(JSON.stringify(chain_headers))
+      })
+
+      scenario('Can perform validation of an entry while the author is offline', async (s, t) => {
+
+        const { alice, bob, carol } = await s.players({alice: one, bob: one, carol: one})
+        // alice and bob start online
+        await alice.spawn()
+        await s.consistency()
+        await bob.spawn()
+        await s.consistency()
+
+        // alice publishes the original entry. !This is an entry that requires full chain validation!
+        const initialContent = "Holo world y'all"
+        const params = { content: initialContent, in_reply_to: null }
+        const create_result = await alice.call('app', "blog", "create_post", params)
+        t.comment(JSON.stringify(create_result))
+        t.equal(create_result.Ok.length, 46)
+        await s.consistency()
+
+        t.comment('waiting for consistency between Alice and Bob')
+        // bob will receive the entry and hold it
+        await s.consistency()
+        t.comment('consistency has been reached')
+
+        // check bob got the content Ok
+        const bob_result = await bob.call('app', "blog", "get_post", { post_address: create_result.Ok })
+        t.ok(bob_result.Ok)
+        t.equal(JSON.parse(bob_result.Ok.App[1]).content, initialContent)
+
+        // alice then goes offline
+        t.comment('waiting for alice to go offline')
+        await alice.kill()
+        t.comment('alice has gone offline')
+
+        // carol then comes online, will receive the entry via gossip from bob and need to validate
+        // Since alice is offline the validation package cannot come direct and must
+        // be regenerated from the published headers (which bob should hold)
+        t.comment('waiting for Carol to come online')
+        await carol.spawn()
+        t.comment('Carol is online')
+
+        t.comment('Waiting for Carol to get all data via gossip')
+        await s.consistency()
+        t.comment('consistency has been reached')
+
+        await delay(50000) // keep this until consistency works with dynamic starting agents
+
+        // Bob now go offline to ensure the following get_post uses carols local store only
+        t.comment('waiting for Bob to go offline')
+        await bob.kill()
+        t.comment('Bob has gone offline')
+
+        t.comment('Waiting for Carol to get post')
+        const carol_result = await carol.call('app', "blog", "get_post", { post_address: create_result.Ok })
+        t.ok(carol_result.Ok, 'Carol get_post does not have truth Ok field')
+        t.equal(JSON.parse(carol_result.Ok.App[1]).content, initialContent)
+      })
+
+    }

app_spec/test/index.js

@@ -3,7 +3,7 @@ const { Orchestrator, tapeExecutor, singleConductor, localOnly, combine, callSyn
 // This constant serves as a check that we haven't accidentally disabled scenario tests.
 // Try to keep this number as close as possible to the actual number of scenario tests.
 // (But never over)
-const MIN_EXPECTED_SCENARIOS = 30
+const MIN_EXPECTED_SCENARIOS = 32
 
 process.on('unhandledRejection', error => {
   console.error('got unhandledRejection:', error);
@@ -41,6 +41,7 @@ require('./files/entry')(orchestrator.registerScenario)
 require('./files/links')(orchestrator.registerScenario)
 require('./files/memo')(orchestrator.registerScenario)
 require('./files/crypto')(orchestrator.registerScenario)
+require('./files/offline-validation')(orchestrator.registerScenario)
 require('./multi-dna')(orchestrator.registerScenario)
 // require('./validate-agent-test')(orchestrator.registerScenario)
 

app_spec/zomes/blog/code/src/blog.rs

@@ -547,6 +547,17 @@ pub fn handle_get_post_bridged(post_address: Address) -> ZomeApiResult<Option<En
     entry
 }
 
+pub fn handle_get_chain_header_hashes() -> ZomeApiResult<Vec<Address>> {
+    match hdk::query_result("**".into(), QueryArgsOptions{ headers: true, ..Default::default()})? {
+        QueryResult::Headers(headers) => {
+            Ok(headers.iter().map(|header| {
+                header.address()
+            }).collect())
+        }
+        _ => unreachable!()
+    }
+}
+
 #[cfg(test)]
 pub mod tests {