Adds the CreateOraclePriceAccount instruction to the TWAP oracle program.
The instruction initialises a canonical OraclePriceAccount PDA for a given
price source and time window, seeding it with a non-zero initial price and
the current block timestamp so the account is immediately valid to consumers.
- PDA mirrors PriceObservations: derived from (oracle_program_id,
price_source_id, window_duration) with a distinct seed constant, so each
(source, window) pair maps to a distinct oracle price account that cannot
collide with its corresponding observations account.
- source_id is not a parameter: it is always set to price_source.account_id.
Accepting it as a free parameter would allow callers to register a price
account that claims to represent a source it does not control. Deriving it
from the authorized price source account closes that vector entirely.
- Authorization follows the same model as CreatePriceObservations:
is_authorized = true on the price source proves the caller controls it; the
PDA check ensures the supplied oracle price account address is the one
derived from that specific source and window.
- The initial timestamp is read from the canonical 1-block LEZ clock
(CLOCK_01_PROGRAM_ACCOUNT_ID), never from a caller-supplied value. The clock
account_id is asserted, so a caller cannot substitute an account they
control to forge the seeding timestamp.
- A zero price or zero timestamp is rejected at creation. Both are the
"no valid price" sentinel consumers treat as unset, so an account must never
be created in that state; the instruction asserts a non-zero initial_price
and a non-zero clock timestamp.
- initial_price is a Q64.64 fixed-point value (real price = initial_price /
2^64), matching the oracle price representation. The non-zero check rejects
the sentinel but cannot validate scale — supplying a correctly-scaled value
is the caller's responsibility.
Closes#129
Adds the CreatePriceObservations instruction to the TWAP oracle program.
The instruction initialises a PriceObservations PDA for a given price
source account and time window, writing the initial tick and timestamp
as the first entry.
Key design decisions:
- Per-window accounts: each (price_source, window_duration) pair maps to
a distinct PriceObservations PDA. The window duration is baked into the
PDA seed so a single price source can support multiple TWAP windows
(24h, 7d, 30d) at independent sampling rates without sharing a buffer.
- window_duration not stored on struct: it is implicit in the PDA address.
Any reader that located the account already knows the window duration
used to derive it. Storing it would be redundant.
- Authorization is implicit: the PriceObservations PDA is derived from
the price source account ID, so is_authorized = true on the price source
proves the caller controls it without a redundant authority field.
- Impersonation is prevented by the PDA check: passing a controlled price
source with a victim's observations account ID fails immediately because
the computed PDA (from the attacker's source) does not match.
Closes#126
