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Merge pull request #26 from vulcanize/canonical_hash_finder

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update canonical header finder functions
This commit is contained in:
Ian Norden 2020-11-13 07:41:46 -06:00 committed by GitHub
commit 013946fd73
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GPG Key ID: 4AEE18F83AFDEB23
11 changed files with 448 additions and 68 deletions
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10
db/migrations/00018_create_check_if_removed_functions.sql
View File

@ -3,7 +3,7 @@
-- returns if a storage node at the provided path was removed in the range > the provided height and <= the provided block hash
CREATE OR REPLACE FUNCTION was_storage_removed(path BYTEA, height BIGINT, hash VARCHAR(66)) RETURNS BOOLEAN
AS $$
SELECT exists(SELECT *
SELECT exists(SELECT 1
FROM eth.storage_cids
INNER JOIN eth.state_cids ON (storage_cids.state_id = state_cids.id)
INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
@ -12,7 +12,8 @@ AS $$
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = hash)
AND storage_cids.node_type = 3);
AND storage_cids.node_type = 3
LIMIT 1);
$$ LANGUAGE SQL;
-- +goose StatementEnd
@ -20,7 +21,7 @@ $$ LANGUAGE SQL;
-- returns if a state node at the provided path was removed in the range > the provided height and <= the provided block hash
CREATE OR REPLACE FUNCTION was_state_removed(path BYTEA, height BIGINT, hash VARCHAR(66)) RETURNS BOOLEAN
AS $$
SELECT exists(SELECT *
SELECT exists(SELECT 1
FROM eth.state_cids
INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
WHERE state_path = path
@ -28,7 +29,8 @@ AS $$
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = hash)
AND state_cids.node_type = 3);
AND state_cids.node_type = 3
LIMIT 1);
$$ LANGUAGE SQL;
-- +goose StatementEnd

121
db/migrations/00019_updated_canonical_hash_finder_functions.sql Normal file
View File

@ -0,0 +1,121 @@
-- +goose Up
-- +goose StatementBegin
CREATE TYPE child_result AS (
has_child BOOLEAN,
children eth.header_cids[]
);
CREATE OR REPLACE FUNCTION has_child(hash VARCHAR(66), height BIGINT) RETURNS child_result AS
$BODY$
DECLARE
child_height INT;
temp_child eth.header_cids;
new_child_result child_result;
BEGIN
child_height = height + 1;
-- short circuit if there are no children
SELECT exists(SELECT 1
FROM eth.header_cids
WHERE parent_hash = hash
AND block_number = child_height
LIMIT 1)
INTO new_child_result.has_child;
-- collect all the children for this header
IF new_child_result.has_child THEN
FOR temp_child IN
SELECT * FROM eth.header_cids WHERE parent_hash = hash AND block_number = child_height
LOOP
new_child_result.children = array_append(new_child_result.children, temp_child);
END LOOP;
END IF;
RETURN new_child_result;
END
$BODY$
LANGUAGE 'plpgsql';
-- +goose StatementEnd
-- +goose StatementBegin
CREATE OR REPLACE FUNCTION canonical_header_from_array(headers eth.header_cids[]) RETURNS eth.header_cids AS
$BODY$
DECLARE
canonical_header eth.header_cids;
canonical_child eth.header_cids;
header eth.header_cids;
current_child_result child_result;
child_headers eth.header_cids[];
current_header_with_child eth.header_cids;
has_children_count INT DEFAULT 0;
BEGIN
-- for each header in the provided set
FOREACH header IN ARRAY headers
LOOP
-- check if it has any children
current_child_result = has_child(header.block_hash, header.block_number);
IF current_child_result.has_child THEN
-- if it does, take note
has_children_count = has_children_count + 1;
current_header_with_child = header;
-- and add the children to the growing set of child headers
child_headers = array_cat(child_headers, current_child_result.children);
END IF;
END LOOP;
-- if none of the headers had children, none is more canonical than the other
IF has_children_count = 0 THEN
-- return the first one selected
SELECT * INTO canonical_header FROM unnest(headers) LIMIT 1;
-- if only one header had children, it can be considered the heaviest/canonical header of the set
ELSIF has_children_count = 1 THEN
-- return the only header with a child
canonical_header = current_header_with_child;
-- if there are multiple headers with children
ELSE
-- find the canonical header from the child set
canonical_child = canonical_header_from_array(child_headers);
-- the header that is parent to this header, is the canonical header at this level
SELECT * INTO canonical_header FROM unnest(headers)
WHERE block_hash = canonical_child.parent_hash;
END IF;
RETURN canonical_header;
END
$BODY$
LANGUAGE 'plpgsql';
-- +goose StatementEnd
-- +goose StatementBegin
CREATE OR REPLACE FUNCTION canonical_header_id(height BIGINT) RETURNS INTEGER AS
$BODY$
DECLARE
canonical_header eth.header_cids;
headers eth.header_cids[];
header_count INT;
temp_header eth.header_cids;
BEGIN
-- collect all headers at this height
FOR temp_header IN
SELECT * FROM eth.header_cids WHERE block_number = height
LOOP
headers = array_append(headers, temp_header);
END LOOP;
-- count the number of headers collected
header_count = array_length(headers, 1);
-- if we have less than 1 header, return NULL
IF header_count IS NULL OR header_count < 1 THEN
RETURN NULL;
-- if we have one header, return its id
ELSIF header_count = 1 THEN
RETURN headers[1].id;
-- if we have multiple headers we need to determine which one is canonical
ELSE
canonical_header = canonical_header_from_array(headers);
RETURN canonical_header.id;
END IF;
END;
$BODY$
LANGUAGE 'plpgsql';
-- +goose StatementEnd
-- +goose Down
DROP FUNCTION canonical_header_id;
DROP FUNCTION canonical_header_from_array;
DROP FUNCTION has_child;
DROP TYPE child_result;

227
db/schema.sql
View File

@ -2,8 +2,8 @@
-- PostgreSQL database dump
--
-- Dumped from database version 12.1
-- Dumped by pg_dump version 12.1
-- Dumped from database version 12.4
-- Dumped by pg_dump version 12.4
SET statement_timeout = 0;
SET lock_timeout = 0;
@ -23,6 +23,58 @@ SET row_security = off;
CREATE SCHEMA eth;
SET default_tablespace = '';
SET default_table_access_method = heap;
--
-- Name: header_cids; Type: TABLE; Schema: eth; Owner: -
--
CREATE TABLE eth.header_cids (
id integer NOT NULL,
block_number bigint NOT NULL,
block_hash character varying(66) NOT NULL,
parent_hash character varying(66) NOT NULL,
cid text NOT NULL,
mh_key text NOT NULL,
td numeric NOT NULL,
node_id integer NOT NULL,
reward numeric NOT NULL,
state_root character varying(66) NOT NULL,
tx_root character varying(66) NOT NULL,
receipt_root character varying(66) NOT NULL,
uncle_root character varying(66) NOT NULL,
bloom bytea NOT NULL,
"timestamp" numeric NOT NULL,
times_validated integer DEFAULT 1 NOT NULL
);
--
-- Name: TABLE header_cids; Type: COMMENT; Schema: eth; Owner: -
--
COMMENT ON TABLE eth.header_cids IS '@name EthHeaderCids';
--
-- Name: COLUMN header_cids.node_id; Type: COMMENT; Schema: eth; Owner: -
--
COMMENT ON COLUMN eth.header_cids.node_id IS '@name EthNodeID';
--
-- Name: child_result; Type: TYPE; Schema: public; Owner: -
--
CREATE TYPE public.child_result AS (
has_child boolean,
children eth.header_cids[]
);
--
-- Name: graphql_subscription(); Type: FUNCTION; Schema: eth; Owner: -
--
@ -78,6 +130,125 @@ END
$$;
--
-- Name: canonical_header_from_array(eth.header_cids[]); Type: FUNCTION; Schema: public; Owner: -
--
CREATE FUNCTION public.canonical_header_from_array(headers eth.header_cids[]) RETURNS eth.header_cids
LANGUAGE plpgsql
AS $$
DECLARE
canonical_header eth.header_cids;
canonical_child eth.header_cids;
header eth.header_cids;
current_child_result child_result;
child_headers eth.header_cids[];
current_header_with_child eth.header_cids;
has_children_count INT DEFAULT 0;
BEGIN
-- for each header in the provided set
FOREACH header IN ARRAY headers
LOOP
-- check if it has any children
current_child_result = has_child(header.block_hash, header.block_number);
IF current_child_result.has_child THEN
-- if it does, take note
has_children_count = has_children_count + 1;
current_header_with_child = header;
-- and add the children to the growing set of child headers
child_headers = array_cat(child_headers, current_child_result.children);
END IF;
END LOOP;
-- if none of the headers had children, none is more canonical than the other
IF has_children_count = 0 THEN
-- return the first one selected
SELECT * INTO canonical_header FROM unnest(headers) LIMIT 1;
-- if only one header had children, it can be considered the heaviest/canonical header of the set
ELSIF has_children_count = 1 THEN
-- return the only header with a child
canonical_header = current_header_with_child;
-- if there are multiple headers with children
ELSE
-- find the canonical header from the child set
canonical_child = canonical_header_from_array(child_headers);
-- the header that is parent to this header, is the canonical header at this level
SELECT * INTO canonical_header FROM unnest(headers)
WHERE block_hash = canonical_child.parent_hash;
END IF;
RETURN canonical_header;
END
$$;
--
-- Name: canonical_header_id(bigint); Type: FUNCTION; Schema: public; Owner: -
--
CREATE FUNCTION public.canonical_header_id(height bigint) RETURNS integer
LANGUAGE plpgsql
AS $$
DECLARE
canonical_header eth.header_cids;
headers eth.header_cids[];
header_count INT;
temp_header eth.header_cids;
BEGIN
-- collect all headers at this height
FOR temp_header IN
SELECT * FROM eth.header_cids WHERE block_number = height
LOOP
headers = array_append(headers, temp_header);
END LOOP;
-- count the number of headers collected
header_count = array_length(headers, 1);
-- if we have less than 1 header, return NULL
IF header_count IS NULL OR header_count < 1 THEN
RETURN NULL;
-- if we have one header, return its id
ELSIF header_count = 1 THEN
RETURN headers[1].id;
-- if we have multiple headers we need to determine which one is canonical
ELSE
canonical_header = canonical_header_from_array(headers);
RETURN canonical_header.id;
END IF;
END;
$$;
--
-- Name: has_child(character varying, bigint); Type: FUNCTION; Schema: public; Owner: -
--
CREATE FUNCTION public.has_child(hash character varying, height bigint) RETURNS public.child_result
LANGUAGE plpgsql
AS $$
DECLARE
child_height INT;
temp_child eth.header_cids;
new_child_result child_result;
BEGIN
child_height = height + 1;
-- short circuit if there are no children
SELECT exists(SELECT 1
FROM eth.header_cids
WHERE parent_hash = hash
AND block_number = child_height
LIMIT 1)
INTO new_child_result.has_child;
-- collect all the children for this header
IF new_child_result.has_child THEN
FOR temp_child IN
SELECT * FROM eth.header_cids WHERE parent_hash = hash AND block_number = child_height
LOOP
new_child_result.children = array_append(new_child_result.children, temp_child);
END LOOP;
END IF;
RETURN new_child_result;
END
$$;
--
-- Name: header_weight(character varying); Type: FUNCTION; Schema: public; Owner: -
--
@ -107,7 +278,7 @@ $$;
CREATE FUNCTION public.was_state_removed(path bytea, height bigint, hash character varying) RETURNS boolean
LANGUAGE sql
AS $$
SELECT exists(SELECT *
SELECT exists(SELECT 1
FROM eth.state_cids
INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
WHERE state_path = path
@ -115,7 +286,8 @@ CREATE FUNCTION public.was_state_removed(path bytea, height bigint, hash charact
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = hash)
AND state_cids.node_type = 3);
AND state_cids.node_type = 3
LIMIT 1);
$$;
@ -126,7 +298,7 @@ $$;
CREATE FUNCTION public.was_storage_removed(path bytea, height bigint, hash character varying) RETURNS boolean
LANGUAGE sql
AS $$
SELECT exists(SELECT *
SELECT exists(SELECT 1
FROM eth.storage_cids
INNER JOIN eth.state_cids ON (storage_cids.state_id = state_cids.id)
INNER JOIN eth.header_cids ON (state_cids.header_id = header_cids.id)
@ -135,52 +307,11 @@ CREATE FUNCTION public.was_storage_removed(path bytea, height bigint, hash chara
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = hash)
AND storage_cids.node_type = 3);
AND storage_cids.node_type = 3
LIMIT 1);
$$;
SET default_tablespace = '';
SET default_table_access_method = heap;
--
-- Name: header_cids; Type: TABLE; Schema: eth; Owner: -
--
CREATE TABLE eth.header_cids (
id integer NOT NULL,
block_number bigint NOT NULL,
block_hash character varying(66) NOT NULL,
parent_hash character varying(66) NOT NULL,
cid text NOT NULL,
mh_key text NOT NULL,
td numeric NOT NULL,
node_id integer NOT NULL,
reward numeric NOT NULL,
state_root character varying(66) NOT NULL,
tx_root character varying(66) NOT NULL,
receipt_root character varying(66) NOT NULL,
uncle_root character varying(66) NOT NULL,
bloom bytea NOT NULL,
"timestamp" numeric NOT NULL,
times_validated integer DEFAULT 1 NOT NULL
);
--
-- Name: TABLE header_cids; Type: COMMENT; Schema: eth; Owner: -
--
COMMENT ON TABLE eth.header_cids IS '@name EthHeaderCids';
--
-- Name: COLUMN header_cids.node_id; Type: COMMENT; Schema: eth; Owner: -
--
COMMENT ON COLUMN eth.header_cids.node_id IS '@name EthNodeID';
--
-- Name: header_cids_id_seq; Type: SEQUENCE; Schema: eth; Owner: -
--

6
pkg/eth/backend.go
View File

@ -55,10 +55,10 @@ var (
const (
RetrieveCanonicalBlockHashByNumber = `SELECT block_hash FROM eth.header_cids
INNER JOIN public.blocks ON (header_cids.mh_key = blocks.key)
WHERE id = (SELECT canonical_header($1))`
WHERE id = (SELECT canonical_header_id($1))`
RetrieveCanonicalHeaderByNumber = `SELECT cid, data FROM eth.header_cids
INNER JOIN public.blocks ON (header_cids.mh_key = blocks.key)
WHERE id = (SELECT canonical_header($1))`
WHERE id = (SELECT canonical_header_id($1))`
RetrieveTD = `SELECT td FROM eth.header_cids
WHERE header_cids.block_hash = $1`
RetrieveRPCTransaction = `SELECT blocks.data, block_hash, block_number, index FROM public.blocks, eth.transaction_cids, eth.header_cids
@ -72,7 +72,7 @@ const (
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = $2)
AND header_cids.id = (SELECT canonical_header(block_number))
AND header_cids.id = (SELECT canonical_header_id(block_number))
ORDER BY block_number DESC
LIMIT 1`
RetrieveCodeByMhKey = `SELECT data FROM public.blocks WHERE key = $1`

57
pkg/eth/eth_state_test.go
View File

@ -61,14 +61,15 @@ func init() {
var _ = Describe("eth state reading tests", func() {
var (
blocks []*types.Block
receipts []types.Receipts
chain *core.BlockChain
db *postgres.DB
api *eth.PublicEthAPI
backend *eth.Backend
chainConfig = params.TestChainConfig
mockTD = big.NewInt(1337)
blocks []*types.Block
receipts []types.Receipts
chain *core.BlockChain
db *postgres.DB
api *eth.PublicEthAPI
backend *eth.Backend
chainConfig = params.TestChainConfig
mockTD = big.NewInt(1337)
expectedCanonicalHeader map[string]interface{}
)
It("test init", func() {
// db and type initializations
@ -90,6 +91,27 @@ var _ = Describe("eth state reading tests", func() {
IntermediateStateNodes: true,
IntermediateStorageNodes: true,
}
canonicalHeader := blocks[1].Header()
expectedCanonicalHeader = map[string]interface{}{
"number": (*hexutil.Big)(canonicalHeader.Number),
"hash": canonicalHeader.Hash(),
"parentHash": canonicalHeader.ParentHash,
"nonce": canonicalHeader.Nonce,
"mixHash": canonicalHeader.MixDigest,
"sha3Uncles": canonicalHeader.UncleHash,
"logsBloom": canonicalHeader.Bloom,
"stateRoot": canonicalHeader.Root,
"miner": canonicalHeader.Coinbase,
"difficulty": (*hexutil.Big)(canonicalHeader.Difficulty),
"extraData": hexutil.Bytes([]byte{}),
"size": hexutil.Uint64(canonicalHeader.Size()),
"gasLimit": hexutil.Uint64(canonicalHeader.GasLimit),
"gasUsed": hexutil.Uint64(canonicalHeader.GasUsed),
"timestamp": hexutil.Uint64(canonicalHeader.Time),
"transactionsRoot": canonicalHeader.TxHash,
"receiptsRoot": canonicalHeader.ReceiptHash,
"totalDifficulty": (*hexutil.Big)(mockTD),
}
// iterate over the blocks, generating statediff payloads, and transforming the data into Postgres
builder := statediff.NewBuilder(chain.StateCache())
for i, block := range blocks {
@ -128,6 +150,17 @@ var _ = Describe("eth state reading tests", func() {
_, err = transformer.Transform(0, payload)
Expect(err).ToNot(HaveOccurred())
}
// Insert some non-canonical data into the database so that we test our ability to discern canonicity
indexAndPublisher := eth2.NewIPLDPublisher(db)
api = eth.NewPublicEthAPI(backend, nil)
err = indexAndPublisher.Publish(test_helpers.MockConvertedPayload)
Expect(err).ToNot(HaveOccurred())
// The non-canonical header has a child
err = indexAndPublisher.Publish(test_helpers.MockConvertedPayloadForChild)
Expect(err).ToNot(HaveOccurred())
err = publishCode(db, test_helpers.ContractCodeHash, test_helpers.ContractCode)
Expect(err).ToNot(HaveOccurred())
})
defer It("test teardown", func() {
eth.TearDownDB(db)
@ -423,4 +456,12 @@ var _ = Describe("eth state reading tests", func() {
Expect(val).To(Equal(hexutil.Bytes{}))
})
})
Describe("eth_getHeaderByNumber", func() {
It("Finds the canonical header based on the header's weight relative to others at the provided height", func() {
header, err := api.GetHeaderByNumber(ctx, number)
Expect(err).ToNot(HaveOccurred())
Expect(header).To(Equal(expectedCanonicalHeader))
})
})
})

4
pkg/eth/ipld_retriever.go
View File

@ -108,7 +108,7 @@ const (
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = $2)
AND header_cids.id = (SELECT canonical_header(block_number))
AND header_cids.id = (SELECT canonical_header_id(block_number))
ORDER BY block_number DESC
LIMIT 1`
RetrieveAccountByLeafKeyAndBlockNumberPgStr = `SELECT state_cids.cid,
@ -151,7 +151,7 @@ const (
AND block_number <= (SELECT block_number
FROM eth.header_cids
WHERE block_hash = $3)
AND header_cids.id = (SELECT canonical_header(block_number))
AND header_cids.id = (SELECT canonical_header_id(block_number))
ORDER BY block_number DESC
LIMIT 1`
)

27
pkg/eth/test_helpers/test_data.go
View File

@ -77,9 +77,21 @@ var (
Extra: []byte{},
},
}
ReceiptsRlp, _ = rlp.EncodeToBytes(MockReceipts)
MockBlock = types.NewBlock(&MockHeader, MockTransactions, MockUncles, MockReceipts)
MockHeaderRlp, _ = rlp.EncodeToBytes(MockBlock.Header())
ReceiptsRlp, _ = rlp.EncodeToBytes(MockReceipts)
MockBlock = types.NewBlock(&MockHeader, MockTransactions, MockUncles, MockReceipts)
MockHeaderRlp, _ = rlp.EncodeToBytes(MockBlock.Header())
MockChildHeader = types.Header{
Time: 0,
Number: new(big.Int).Add(BlockNumber, common.Big1),
Root: common.HexToHash("0x0"),
TxHash: common.HexToHash("0x0"),
ReceiptHash: common.HexToHash("0x0"),
Difficulty: big.NewInt(5000001),
Extra: []byte{},
ParentHash: MockBlock.Header().Hash(),
}
MockChild = types.NewBlock(&MockChildHeader, MockTransactions, MockUncles, MockReceipts)
MockChildRlp, _ = rlp.EncodeToBytes(MockChild.Header())
Address = common.HexToAddress("0xaE9BEa628c4Ce503DcFD7E305CaB4e29E7476592")
AnotherAddress = common.HexToAddress("0xaE9BEa628c4Ce503DcFD7E305CaB4e29E7476593")
ContractAddress = crypto.CreateAddress(SenderAddr, MockTransactions[2].Nonce())
@ -351,6 +363,15 @@ var (
StorageNodes: MockStorageNodes,
StateNodes: MockStateNodes,
}
MockConvertedPayloadForChild = eth.ConvertedPayload{
TotalDifficulty: MockChild.Difficulty(),
Block: MockChild,
Receipts: MockReceipts,
TxMetaData: MockTrxMeta,
ReceiptMetaData: MockRctMeta,
StorageNodes: MockStorageNodes,
StateNodes: MockStateNodes,
}
MockCIDWrapper = &eth2.CIDWrapper{
BlockNumber: new(big.Int).Set(BlockNumber),

16
pkg/rpc/check.go
View File

@ -1,3 +1,19 @@
// VulcanizeDB
// Copyright © 2020 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package rpc
import "github.com/ethereum/go-ethereum/rpc"

16
pkg/rpc/http.go
View File

@ -1,3 +1,19 @@
// VulcanizeDB
// Copyright © 2020 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (

16
pkg/rpc/ipc.go
View File

@ -1,3 +1,19 @@
// VulcanizeDB
// Copyright © 2020 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (

16
pkg/rpc/ws.go
View File

@ -1,3 +1,19 @@
// VulcanizeDB
// Copyright © 2020 Vulcanize
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package rpc
import (