Struct Logger

pub struct Logger<'a, S: Db> { /* private fields */ }

Logger instance that is created over a key-value storage for a given contract-id

The logger is essentially a ring-buffer with a fixed size, that uses a specific key-space.

Implementations

impl<'a, S: Db> Logger<'a, S>

pub fn new(db: &'a S, id: impl Into<Id>) -> Self

pub fn flush_lines( &self, lines: &[LogLine], db_ptr: &S::Handle, txn: &mut <S as Db>::RwTx<'_>, ) -> Result<()>

Flushes the given log lines into the ring-buffer.

This function writes a batch of log lines into the underlying key-value storage. It performs the following steps:

1. Reads the current buffer metadata, which includes the logical start and end indices of the stored log lines.
2. Determines if adding the new log lines would exceed the fixed capacity (MAX_LOG_BUFFER_SIZE). If so, it advances the start index to overwrite the oldest entries.
3. Records the flush metadata (last_flush_start and last_flush_count) to track the range of log lines added in this flush.
4. Writes the new log lines to storage using modulo arithmetic to map the logical indices to physical storage keys.
5. Updates and persists the modified metadata.

Arguments

• lines - A slice of LogLine objects to be flushed into the buffer.

Returns

• Ok(()) if the flush is successful.

Errors

Returns an error if any database operation fails or if serialization/deserialization of log lines or metadata fails.

pub fn get_full_log(&self) -> Result<Vec<LogLine>>

Retrieves the full log from the buffer in chronological order.

pub fn get_log_lines( &self, start_offset: u64, count: u64, ) -> Result<Vec<LogLine>>

Retrieves a range of log lines from the buffer in chronological order.

Arguments

• start_offset - The number of log lines to skip from the oldest entry.
• count - The maximum number of log lines to retrieve.

For example, to get the 100 oldest log lines, call with start_offset = 0 and count = 100.

pub fn get_last_log(&self) -> Result<Vec<LogLine>>

Retrieves the log lines that were flushed in the last call to flush_lines.

pub fn total_log_lines(&self) -> Result<u64>

Returns the total number of log lines ever flushed.

Note that this number is the absolute index of the last flushed log line, so if logs have been overwritten in the ring-buffer, the current log count (meta.end - meta.start) may be lower.

pub fn get_logs_paginated( &self, pagination: Pagination, ) -> Result<PaginatedElements<LogLine>>

Retrieves log lines for the given page and the total number of pages.