ic-query 0.93.3

//! Module: cache::completeness
//!
//! Responsibility: define and validate complete paged-collection evidence.
//! Does not own: family cache envelopes, row validation, or filesystem IO.
//! Boundary: preserves the raw persisted status while centralizing the one
//! complete-collection contract shared by NNS, SNS, and ICRC caches.

use serde::{Deserialize as SerdeDeserialize, Serialize};

const API_EXHAUSTED_STATUS: &str = "api_exhausted";

///
/// CacheCollectionCompleteness
///
/// Persisted evidence that a paged cache collection exhausted its source API.
///

#[derive(Clone, Debug, Eq, PartialEq, SerdeDeserialize, Serialize)]
pub struct CacheCollectionCompleteness {
    /// Raw persisted completeness status; complete collections use `api_exhausted`.
    pub status: String,
    /// Maximum rows requested per page, or observed width of an unpaged inventory (at least one).
    pub page_size: u32,
    /// Number of source pages collected.
    pub page_count: u32,
    /// Number of unique rows retained in the complete cache.
    pub row_count: usize,
    /// Whether every page is guaranteed to describe one source instant.
    pub point_in_time_guaranteed: bool,
}

impl CacheCollectionCompleteness {
    /// Construct evidence for an API-exhausted paged collection.
    #[must_use]
    pub fn api_exhausted(
        page_size: u32,
        page_count: u32,
        row_count: usize,
        point_in_time_guaranteed: bool,
    ) -> Self {
        Self {
            status: API_EXHAUSTED_STATUS.to_string(),
            page_size,
            page_count,
            row_count,
            point_in_time_guaranteed,
        }
    }

    /// Return whether the raw status claims source API exhaustion.
    #[must_use]
    pub fn is_api_exhausted(&self) -> bool {
        self.status == API_EXHAUSTED_STATUS
    }
}

/// Validate shared API-exhaustion, page, and row-count evidence.
pub fn validate_cache_collection_completeness(
    completeness: &CacheCollectionCompleteness,
    actual_row_count: usize,
) -> Result<(), String> {
    if !completeness.is_api_exhausted() {
        return Err(format!(
            "completeness status is {}, expected {API_EXHAUSTED_STATUS}",
            completeness.status
        ));
    }
    if completeness.page_size == 0 {
        return Err("completeness page_size must be greater than zero".to_string());
    }
    if completeness.page_count == 0 {
        return Err("completeness page_count must be greater than zero".to_string());
    }
    if completeness.row_count != actual_row_count {
        return Err(format!(
            "completeness row_count is {}, actual row count is {actual_row_count}",
            completeness.row_count
        ));
    }
    let maximum_row_count = u64::from(completeness.page_size) * u64::from(completeness.page_count);
    if actual_row_count as u128 > u128::from(maximum_row_count) {
        return Err(format!(
            "completeness row_count is {actual_row_count}, maximum for {} pages of size {} is {maximum_row_count}",
            completeness.page_count, completeness.page_size
        ));
    }
    Ok(())
}

#[cfg(test)]
mod tests;