Function format_size_pretty

src/functions/system_functions.rs:473–516

Format size in bytes as human-readable string using PostgreSQL's algorithm Uses binary prefixes: 1 kB = 1024 bytes, 1 MB = 1024² bytes, etc. Based on PostgreSQL source code in src/backend/utils/adt/dbsize.c

(mut size: i64)

/// Uses binary prefixes: 1 kB = 1024 bytes, 1 MB = 1024² bytes, etc.
/// Based on PostgreSQL source code in src/backend/utils/adt/dbsize.c
fn format_size_pretty(mut size: i64) -> String {
    let abs_size = size.unsigned_abs();

    // PostgreSQL unit definitions
    const BYTES_LIMIT: u64 = 10 * 1024;  // 10240 bytes
    const UNIT_LIMIT: u64 = 10 * 1024;  // 10240 (for kB, MB, GB, TB, PB)

    // Check if we should display as bytes
    if abs_size < BYTES_LIMIT {
        return format!("{} bytes", size);
    }

    // Convert to kB and check limit
    size = (size + 512) / 1024; // Half-rounded division
    let abs_size_kb = size.unsigned_abs();
    if abs_size_kb < UNIT_LIMIT {
        return format!("{} kB", size);
    }

    // Convert to MB and check limit
    size = (size + 512) / 1024; // Half-rounded division
    let abs_size_mb = size.unsigned_abs();
    if abs_size_mb < UNIT_LIMIT {
        return format!("{} MB", size);
    }

    // Convert to GB and check limit
    size = (size + 512) / 1024; // Half-rounded division
    let abs_size_gb = size.unsigned_abs();
    if abs_size_gb < UNIT_LIMIT {
        return format!("{} GB", size);
    }

    // Convert to TB and check limit
    size = (size + 512) / 1024; // Half-rounded division
    let abs_size_tb = size.unsigned_abs();
    if abs_size_tb < UNIT_LIMIT {
        return format!("{} TB", size);
    }

    // Convert to PB (final unit)
    size = (size + 512) / 1024; // Half-rounded division
    format!("{} PB", size)
}

#[cfg(test)]
mod tests {