hydrate

Hydrate

Build hydratePayload bytes for HydrateProxy (hydrateExecute / hydrateExecuteAndSweep in trails-contracts) by resolving patch targets with abicalldata Selector and ByteRange instead of hand-counting calldata offsets.

This package depends on abicalldata for selector types and for building selectors with abicalldata.NewPath() (or abicalldata.NewRangeSelector for fixed offsets).

Usage

payload := v3.NewCallsPayload(...)

// Selector must resolve to exactly one range on the target call (same index as ForCall).
permitOwner := abicalldata.NewPath().
    CallData(0).
    ABI(trailsABI, "hydrateExecute").
    ArgBytesData("packedPayload").
    EncodedCallsPayload().
    EncodedCallData(0).
    ABI(erc2612ABI, "permit").
    ArgSlot("owner").
    AsSelector()

b := hydrate.NewBuilder(&payload)

if err := b.ForCall(0).DataAddress(permitOwner, hydrate.SourceSelf()); err != nil {
    return err
}

hydratePayload, err := b.Build()
if err != nil {
    return err
}
// nil/empty hydratePayload means "no hydration" (contract skips hydration).

calldata, err := hydrate.PackHydrateExecute(packedPayload, hydratePayload)

With sweep after execution:

calldata, err := hydrate.PackHydrateExecuteAndSweep(
    packedPayload,
    hydratePayload,
    sweepTarget,
    tokensToSweep,
    sweepNative,
)

If ABI parameters are unnamed, use index-based steps such as ArgSlotIndex / ArgBytesDataIndex on abicalldata.NewPath() (see the abicalldata README).

Call sections and ordering

• Use ForCall(tindex) for each packed call you want to hydrate. Multiple methods on the same ForCall append commands to that call's section.
• Build() emits sections in ascending tindex order, each as: [tindex byte][commands…][0x00]. That order matches how the proxy walks the stream while executing calls; sections must not be reordered arbitrarily.

Address sources

Data patches and CallTo / CallValue use a low nibble on the command byte; optional literals append 20 bytes when needed:

Selectors

Each Data* method requires an abicalldata.Selector that resolves to exactly one abicalldata.ByteRange, and that range's CallIndex must equal the ForCall index. The range's offset within that call's data becomes the patch offset (uint16); the builder checks that 20-byte (address) or 32-byte (uint256) replacements fit.

For unit tests or fixed layouts, abicalldata.NewRangeSelector(callIndex, offset, size) returns a selector backed by an explicit range.

When using a multi-step path into nested calldata, ABI context is cleared after any step that narrows the active range or switches to a new byte frame (including .Slice, .ArgBytesData, .ArgBytesDataIndex, .ArgBytesEncoded, .EncodedCallsPayload, .EncodedCallData). Call .ABI(contractABI, method) again before .ArgSlot, .ArgSlotIndex, .ArgBytesData, .ArgBytesDataIndex, or .ArgBytesEncoded on that frame.