add(rpc): Adds `getblockheader` RPC method #8967

arya2 · 2024-10-25T03:56:16Z

Motivation

This is needed for block explorer support and has been requested by a mining pool.

Closes #8442.
Part of #8446 (always includes height in response when called with verbosity = 2).

Specifications & References

https://zcash.github.io/rpc/getblockheader.html

Solution

Adds a getblockheader RPC method like the one in zcashd

Related changes:

Adds height field to getblock response when called with a height if verbosity == 2

Tests

Adds a snapshot test for querying by height/hash and with verbose being true/false
Adds a vectors test

PR Author's Checklist

The PR name will make sense to users.
The solution is tested.
The documentation is up to date.
The PR has a priority label.

PR Reviewer's Checklist

The PR Author's checklist is complete.
The PR resolves the issue.

… response

… impl for sapling::tree::Root, adds snapshot and vector tests for new RPC method, adds snapshots.

arya2 · 2024-10-25T21:51:43Z

zcash-rpc-diff util output with verbose = true:

 {
   "hash": "000000002c2063bab0acae547bab7e0309db8e1b7003e9c01eb423c0166d5ac9",
-  "confirmations": 2683651,
+  "confirmations": 169203,
   "height": 10000,
   "version": 4,
   "merkleroot": "e093171fc092c4bc0598c6d475489f892b177e3c6139ca680b064787093e2d1e",
-  "finalsaplingroot": "fbc2f4300c01f0b7820d00e3347c8da4ee614674376cbc45359daa54f9b5493e",
+  "finalsaplingroot": "0000000000000000000000000000000000000000000000000000000000000000",
   "time": 1479096667,
   "nonce": "000000000000000000000000000004cc00000000000000000000000000000000",
+  "solution": "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",
   "bits": "1d01bf9d",
-  "difficulty": "00000001bf9d0000000000000000000000000000000000000000000000000000",
+  "difficulty": 299851.4066097095,
+  "chainwork": "00000000000000000000000000000000000000000000000000000a13fdd5bc69",
   "previousblockhash": "000000001298a3685fbc493751ff2309a9bcef7cefad4565642bafb43f71b4c6",
   "nextblockhash": "00000000980d28a4bd926c4c553f7eaa5b29d3a78e8423f3863b72edd258839e"
 }

It matches exactly when verbose is false, but the difficulty and finalsaplingroot fields aren't matching. It's possible the finalsaplingroot field will match after Sapling activation (my zcashd is still syncing). zcashd also includes solution and chainwork fields, solution should be trivial to add, chainwork may be a little more complicated.

Update:

The finalsaplingroot does match after Sapling activation, though it was reversed.

Now it's just the difficulty field that's different, and the solution and chainwork fields that are missing.

Update 2:

The RPC is still missing the chainwork field but otherwise matches the zcashd output exactly, including while the Sapling note commitment tree is empty.

The chainwork field is confirmed to be the cumulative work in the chain, which Zebra doesn't store in the finalized state. It's also undocumented so we can probably leave it until/unless someone requests it. It could also still be calculated by the caller by summing up the work for the chain up to the requested block.

…er to handle it now than risk debugging it later)

…rder.

zebra-rpc/src/methods.rs

…t the `chainwork` field), updates snapshots, and avoids a possible panic when there's a chain reorg between state queries.

arya2 · 2024-10-28T20:46:01Z

zebra-chain/src/work/difficulty.rs

+    pub fn relative_to_network(&self, network: &Network) -> f64 {
+        let network_difficulty = network.target_difficulty_limit().to_compact();
+
+        let [mut n_shift, ..] = self.0.to_be_bytes();
+        let [n_shift_amount, ..] = network_difficulty.0.to_be_bytes();
+        let mut d_diff = f64::from(network_difficulty.0 << 8) / f64::from(self.0 << 8);
+
+        while n_shift < n_shift_amount {
+            d_diff *= 256.0;
+            n_shift += 1;
+        }
+
+        while n_shift > n_shift_amount {
+            d_diff /= 256.0;
+            n_shift -= 1;
+        }
+
+        d_diff
+    }


This was copied from zcashd here: https://github.com/zcash/zcash/blob/master/src/rpc/blockchain.cpp#L34-L74.

Should we credit it in a comment or something?

Adds getblockheader RPC method

108de07

arya2 added A-rpc Area: Remote Procedure Call interfaces P-Medium ⚡ labels Oct 25, 2024

arya2 added this to the Zebra can replace `zcashd` milestone Oct 25, 2024

arya2 self-assigned this Oct 25, 2024

Updates snapshots, adds hash/height/next_block_hash fields to verbose…

1a71591

… response

arya2 changed the title ~~Add(rpc): Adds getblockheader RPC method~~ add(rpc): Adds getblockheader RPC method Oct 25, 2024

arya2 added 2 commits October 25, 2024 16:51

updates getblock snapshot

91a199c

updates getblockheader response type to hex-encode fields, adds ToHex…

d693a49

… impl for sapling::tree::Root, adds snapshot and vector tests for new RPC method, adds snapshots.

arya2 marked this pull request as ready for review October 25, 2024 20:53

arya2 requested review from a team as code owners October 25, 2024 20:53

arya2 requested review from upbqdn and removed request for a team October 25, 2024 20:53

rustfmt

4379d62

arya2 added the A-state Area: State / database changes label Oct 25, 2024

arya2 marked this pull request as draft October 25, 2024 21:29

fixes snapshots, matches zcashd more closely

a48693c

arya2 marked this pull request as ready for review October 25, 2024 21:48

arya2 added 3 commits October 25, 2024 18:29

fixes vectors test

f17b449

updates lwd failure messages (probably doesn't matter, but seems bett…

df7d0a4

…er to handle it now than risk debugging it later)

fixes getblock_rpc test, fixes/reverses finalsaplingroot field byte-o…

068762b

…rder.

arya2 commented Oct 26, 2024

View reviewed changes

zebra-rpc/src/methods.rs Outdated Show resolved Hide resolved

arya2 added the do-not-merge Tells Mergify not to merge this PR label Oct 26, 2024

arya2 requested a review from natalieesk October 28, 2024 16:41

fixes vector test, addresses remaining differences with zcashd (excep…

80ea07b

…t the `chainwork` field), updates snapshots, and avoids a possible panic when there's a chain reorg between state queries.

arya2 commented Oct 28, 2024

View reviewed changes

arya2 removed the do-not-merge Tells Mergify not to merge this PR label Oct 31, 2024

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add(rpc): Adds `getblockheader` RPC method #8967

add(rpc): Adds `getblockheader` RPC method #8967

arya2 commented Oct 25, 2024 •

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arya2 commented Oct 25, 2024 •

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arya2 Oct 28, 2024

mpguerra Oct 29, 2024

add(rpc): Adds getblockheader RPC method #8967

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add(rpc): Adds getblockheader RPC method #8967

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arya2 commented Oct 25, 2024 • edited Loading

Motivation

Specifications & References

Solution

Tests

PR Author's Checklist

PR Reviewer's Checklist

arya2 commented Oct 25, 2024 • edited Loading

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add(rpc): Adds `getblockheader` RPC method #8967

add(rpc): Adds `getblockheader` RPC method #8967

arya2 commented Oct 25, 2024 •

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arya2 commented Oct 25, 2024 •

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