You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
100 lines
3.0 KiB
100 lines
3.0 KiB
Indexing Transactions
|
|
=====================
|
|
|
|
Tendermint allows you to index transactions and later query or subscribe to
|
|
their results.
|
|
|
|
Let's take a look at the ``[tx_index]`` config section:
|
|
|
|
::
|
|
|
|
##### transactions indexer configuration options #####
|
|
[tx_index]
|
|
|
|
# What indexer to use for transactions
|
|
#
|
|
# Options:
|
|
# 1) "null" (default)
|
|
# 2) "kv" - the simplest possible indexer, backed by key-value storage (defaults to levelDB; see DBBackend).
|
|
indexer = "kv"
|
|
|
|
# Comma-separated list of tags to index (by default the only tag is tx hash)
|
|
#
|
|
# It's recommended to index only a subset of tags due to possible memory
|
|
# bloat. This is, of course, depends on the indexer's DB and the volume of
|
|
# transactions.
|
|
index_tags = ""
|
|
|
|
# When set to true, tells indexer to index all tags. Note this may be not
|
|
# desirable (see the comment above). IndexTags has a precedence over
|
|
# IndexAllTags (i.e. when given both, IndexTags will be indexed).
|
|
index_all_tags = false
|
|
|
|
By default, Tendermint will index all transactions by their respective hashes
|
|
using an embedded simple indexer. Note, we are planning to add more options in
|
|
the future (e.g., Postgresql indexer).
|
|
|
|
Adding tags
|
|
-----------
|
|
|
|
In your application's ``DeliverTx`` method, add the ``Tags`` field with the
|
|
pairs of UTF-8 encoded strings (e.g. "account.owner": "Bob", "balance":
|
|
"100.0", "date": "2018-01-02").
|
|
|
|
Example:
|
|
|
|
::
|
|
|
|
func (app *KVStoreApplication) DeliverTx(tx []byte) types.Result {
|
|
...
|
|
tags := []cmn.KVPair{
|
|
{[]byte("account.name"), []byte("igor")},
|
|
{[]byte("account.address"), []byte("0xdeadbeef")},
|
|
{[]byte("tx.amount"), []byte("7")},
|
|
}
|
|
return types.ResponseDeliverTx{Code: code.CodeTypeOK, Tags: tags}
|
|
}
|
|
|
|
If you want Tendermint to only index transactions by "account.name" tag, in the
|
|
config set ``tx_index.index_tags="account.name"``. If you to index all tags,
|
|
set ``index_all_tags=true``
|
|
|
|
Note, there are a few predefined tags:
|
|
|
|
- ``tm.event`` (event type)
|
|
- ``tx.hash`` (transaction's hash)
|
|
- ``tx.height`` (height of the block transaction was committed in)
|
|
|
|
Tendermint will throw a warning if you try to use any of the above keys.
|
|
|
|
Quering transactions
|
|
--------------------
|
|
|
|
You can query the transaction results by calling ``/tx_search`` RPC endpoint:
|
|
|
|
::
|
|
|
|
curl "localhost:46657/tx_search?query=\"account.name='igor'\"&prove=true"
|
|
|
|
Check out `API docs <https://tendermint.github.io/slate/?shell#txsearch>`__ for more
|
|
information on query syntax and other options.
|
|
|
|
Subscribing to transactions
|
|
---------------------------
|
|
|
|
Clients can subscribe to transactions with the given tags via Websocket by
|
|
providing a query to ``/subscribe`` RPC endpoint.
|
|
|
|
::
|
|
|
|
{
|
|
"jsonrpc": "2.0",
|
|
"method": "subscribe",
|
|
"id": "0",
|
|
"params": {
|
|
"query": "account.name='igor'"
|
|
}
|
|
}
|
|
|
|
Check out `API docs <https://tendermint.github.io/slate/#subscribe>`__ for more
|
|
information on query syntax and other options.
|