Skip to content

Commit

Permalink
docs cleanup
Browse files Browse the repository at this point in the history
  • Loading branch information
@benesjan
benesjan committed Dec 13, 2024
1 parent 01cf7ca commit 372889c
Showing 1 changed file with 45 additions and 33 deletions.
78 changes: 45 additions & 33 deletions yarn-project/pxe/src/simulator_oracle/index.ts
View file
Original file line number Diff line number Diff line change
Expand Up @@ -424,37 +424,32 @@ export class SimulatorOracle implements DBOracle {
// Half the size of the window we slide over the tagging secret indexes.
const WINDOW_HALF_SIZE = 10;

// Ideally this algorithm would be implemented in noir, exposing its building blocks as oracles.
// However it is impossible at the moment due to the language not supporting nested slices.
// This nesting is necessary because for a given set of tags we don't
// know how many logs we will get back. Furthermore, these logs are of undetermined
// length, since we don't really know the note they correspond to until we decrypt them.

const recipients = scopes ? scopes : await this.keyStore.getAccounts();
// A map of logs going from recipient address to logs. Note that the logs might have been processed before
// due to us having a sliding window that "looks back" for logs as well. (We look back as there is no guarantee
// that a logs will be received ordered by a given tax index and that the tags won't be reused).
const logsMap = new Map<string, TxScopedL2Log[]>();
// const contractName = await this.contractDataOracle.getDebugContractName(contractAddress);
const contractName = await this.contractDataOracle.getDebugContractName(contractAddress);
for (const recipient of recipients) {
const logsForRecipient: TxScopedL2Log[] = [];
// Ideally this algorithm would be implemented in noir, exposing its building blocks as oracles.
// However it is impossible at the moment due to the language not supporting nested slices.
// This nesting is necessary because for a given set of tags we don't
// know how many logs we will get back. Furthermore, these logs are of undetermined
// length, since we don't really know the note they correspond to until we decrypt them.

// 1. Get all the secrets for the recipient and sender pairs (#9365)
// Get all the secrets for the recipient and sender pairs (#9365)
const secrets = await this.#getIndexedTaggingSecretsForContacts(contractAddress, recipient);

// 1.1 Set up a sliding window with an offset. Chances are the sender might have messed up
// and inadvertently incremented their index without us getting any logs (for example, in case
// of a revert). If we stopped looking for logs the first time we don't receive any logs for a tag,
// we might never receive anything from that sender again.
// Also there's a possibility that we have advanced our index, but the sender has reused it,
// so we might have missed some logs. For these reasons, we have to look both back and ahead of
// the stored index.

// As we iterate we store the largest index we have seen for a given secret to later on store it in the db.
const newLargestIndexMapToStore: { [k: string]: number } = {};

// The initial/unmodified indexes of the secrets stored in a key-value map where key is the app tagging secret.
const initialIndexesMap = getInitialIndexesMap(secrets);

// We fetch logs for a window of indexes in a range:
// <latest_log_index - WINDOW_HALF_SIZE, latest_log_index + WINDOW_HALF_SIZE>.
//
// We use this window approach because it could happen that a sender might have messed up and inadvertently
// incremented their index without us getting any logs (for example, in case of a revert). If we stopped looking
// for logs the first time we don't receive any logs for a tag, we might never receive anything from that sender again.
// Also there's a possibility that we have advanced our index, but the sender has reused it, so we might have missed
// some logs. For these reasons, we have to look both back and ahead of the stored index.
let secretsAndWindows = secrets.map(secret => {
return {
appTaggingSecret: secret.appTaggingSecret,
Expand All @@ -463,6 +458,12 @@ export class SimulatorOracle implements DBOracle {
};
});

// As we iterate we store the largest index we have seen for a given secret to later on store it in the db.
const newLargestIndexMapToStore: { [k: string]: number } = {};

// The initial/unmodified indexes of the secrets stored in a key-value map where key is the app tagging secret.
const initialIndexesMap = getInitialIndexesMap(secrets);

while (secretsAndWindows.length > 0) {
const secretsForTheWholeWindow = getIndexedTaggingSecretsForTheWindow(secretsAndWindows);
const tagsForTheWholeWindow = secretsForTheWholeWindow.map(secret =>
Expand All @@ -478,14 +479,21 @@ export class SimulatorOracle implements DBOracle {

logsByTags.forEach((logsByTag, logIndex) => {
if (logsByTag.length > 0) {
// The logs for the given tag exist so I add them for later processing
// The logs for the given tag exist so we store them for later processing
logsForRecipient.push(...logsByTag);

// I fetch the indexed tagging secret corresponding to the log as I need that to evaluate whether
// We the indexed tagging secret corresponding to the log as I need that to evaluate whether
// a new largest index have been found.
const secretCorrespondingToLog = secretsForTheWholeWindow[logIndex];
const initialIndex = initialIndexesMap[secretCorrespondingToLog.appTaggingSecret.toString()];

this.log.debug(`Found ${logsByTag.length} logs as recipient ${recipient}`, {
recipient,
secret: secretCorrespondingToLog.appTaggingSecret,
contractName,
contractAddress,
});

if (
secretCorrespondingToLog.index >= initialIndex &&
(newLargestIndexMapForIteration[secretCorrespondingToLog.appTaggingSecret.toString()] === undefined ||
Expand All @@ -496,27 +504,31 @@ export class SimulatorOracle implements DBOracle {
// the difference of the window sets of current and the next iteration)
newLargestIndexMapForIteration[secretCorrespondingToLog.appTaggingSecret.toString()] =
secretCorrespondingToLog.index + 1;
}


this.log.debug(
`Incrementing index to ${
secretCorrespondingToLog.index + 1
} at contract ${contractName}(${contractAddress})`,
);
}
}
});

// Now based on the new largest indexes we found, I will construct a new secrets and windows set to fetch logs
// for. Note that we it's very unlikely that a new log from the current window would appear between
// the iterations so we fetch the logs only for the difference of the window sets.
// Now based on the new largest indexes we found, we will construct a new secrets and windows set to fetch logs
// for. Note that it's very unlikely that a new log from the current window would appear between the iterations
// so we fetch the logs only for the difference of the window sets.
const newSecretsAndWindows = [];
for (const [appTaggingSecret, newIndex] of Object.entries(newLargestIndexMapForIteration)) {
const secret = secrets.find(secret => secret.appTaggingSecret.toString() === appTaggingSecret);
if (secret) {
newSecretsAndWindows.push({
appTaggingSecret: secret.appTaggingSecret,
// We set the left most index to the new largest index + 1 to avoid fetching the same logs again
// We set the left most index to the new index to avoid fetching the same logs again
leftMostIndex: newIndex,
rightMostIndex: newIndex + WINDOW_HALF_SIZE,
});

// We store the new largest index in the map to store it in the db.
// We store the new largest index in the map to later store it in the db.
newLargestIndexMapToStore[appTaggingSecret] = newIndex;
} else {
throw new Error(
Expand All @@ -525,17 +537,17 @@ export class SimulatorOracle implements DBOracle {
}
}

// Now we set the new secrets and windows and proceed to the next iteration
// Now we set the new secrets and windows and proceed to the next iteration.
secretsAndWindows = newSecretsAndWindows;
}

// We filter the logs by block number and store them in the map
// We filter the logs by block number and store them in the map.
logsMap.set(
recipient.toString(),
logsForRecipient.filter(log => log.blockNumber <= maxBlockNumber),
);

// At this point we have processed all the logs for the recipient so we store the new largest indexes in the db
// At this point we have processed all the logs for the recipient so we store the new largest indexes in the db.
await this.db.setTaggingSecretsIndexesAsRecipient(
Object.entries(newLargestIndexMapToStore).map(
([appTaggingSecret, index]) => new IndexedTaggingSecret(Fr.fromHexString(appTaggingSecret), index),
Expand Down

0 comments on commit 372889c

Please sign in to comment.