blockworks-foundation
/
solana
mirror of https://github.com/blockworks-foundation/solana.git
1
0
Fork 0
Code Issues Projects Releases Wiki Activity

docs: update spl token exchange integration (#19573) 

* docs: update spl token exchange integration

* Apply suggestions from code review

Co-authored-by: Michael Vines <mvines@gmail.com>

Co-authored-by: Michael Vines <mvines@gmail.com>
This commit is contained in:
Trent Nelson 2021-09-02 11:32:08 -06:00 committed by GitHub
parent f5388cfe71
commit f4f14c42bb
No known key found for this signature in database
GPG Key ID: 4AEE18F83AFDEB23
2 changed files with 19 additions and 19 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
docs/src/integrations/exchange.md
View File

@ -694,35 +694,35 @@ Signature: 3R6tsog17QM8KfzbcbdP4aoMfwgo6hBggJDVy7dZPVmH2xbCWjEj31JKD53NzMrf25ChF
### Depositing
Since each `(user, mint)` pair requires a separate account on chain, it is
recommended that an exchange create batches of token accounts in advance and assign them
to users on request. These accounts should all be owned by exchange-controlled
keypairs.
Since each `(wallet, mint)` pair requires a separate account on chain. It is
recommended that the addresses for these accounts be derived from SOL deposit
wallets using the
[Associated Token Account](https://spl.solana.com/associated-token-account) (ATA)
scheme and that _only_ deposits from ATA addresses be accepted.
Monitoring for deposit transactions should follow the [block polling](#poll-for-blocks)
method described above. Each new block should be scanned for successful transactions
issuing SPL Token [Transfer](https://github.com/solana-labs/solana-program-library/blob/096d3d4da51a8f63db5160b126ebc56b26346fc8/token/program/src/instruction.rs#L92)
or [Transfer2](https://github.com/solana-labs/solana-program-library/blob/096d3d4da51a8f63db5160b126ebc56b26346fc8/token/program/src/instruction.rs#L252)
instructions referencing user accounts, then querying the
[token account balance](developing/clients/jsonrpc-api.md#gettokenaccountbalance)
updates.
[Considerations](https://github.com/solana-labs/solana/issues/12318) are being
made to exend the `preBalance` and `postBalance` transaction status metadata
fields to include SPL Token balance transfers.
issuing SPL Token [Transfer](https://github.com/solana-labs/solana-program-library/blob/fc0d6a2db79bd6499f04b9be7ead0c400283845e/token/program/src/instruction.rs#L105)
or [TransferChecked](https://github.com/solana-labs/solana-program-library/blob/fc0d6a2db79bd6499f04b9be7ead0c400283845e/token/program/src/instruction.rs#L268)
instructions referencing user accounts. It is possible that a transfer is initiated
by a smart contract via [Cross Program Invocation](/developing/programming-model/calling-between-programs#cross-program-invocations),
so [inner instructions](/terminology#inner-instruction) must be checked as well.
The `preTokenBalance` and `postTokenBalance` fields from the transaction's metadata
must then be used to determine the effective balance change.
### Withdrawing
The withdrawal address a user provides should be the same address used for
regular SOL withdrawal.
The withdrawal address a user provides must be the that of their SOL wallet.
Before executing a withdrawal [transfer](#token-transfers),
the exchange should check the address as
[described above](#validating-user-supplied-account-addresses-for-withdrawals).
Additionally this address must be owned by the System Program and have no account data. If the address has no SOL balance, user confirmation should be obtained before proceeding with the withdrawal. All other withdrawal addresses must be rejected.
From the withdrawal address, the associated token account for the correct mint
determined and the transfer issued to that account. Note that it's possible
that the associated token account does not yet exist, at which point the
From the withdrawal address, the [Associated Token Account](https://spl.solana.com/associated-token-account)
(ATA) for the correct mint is derived and the transfer issued to that account via a
[TransferChecked](https://github.com/solana-labs/solana-program-library/blob/fc0d6a2db79bd6499f04b9be7ead0c400283845e/token/program/src/instruction.rs#L268)
instruction. Note that it is possible that the ATA address does not yet exist, at which point the
exchange should fund the account on behalf of the user. For SPL Token v2
accounts, funding the withdrawal account will require 0.00203928 SOL (2,039,280
lamports).

2
docs/src/terminology.md
View File

@ -139,7 +139,7 @@ An increase in token supply over time used to fund rewards for validation and to
## inner instruction
See [cross-program invocation](terminology.md#cross-program-invocation).
See [cross-program invocation](terminology.md#cross-program-invocation-cpi).
## instruction