wedb_embed 0.1.2

Embedded database engine providing Redis-like APIs, built on fjall / 嵌入式数据库引擎，提供类似 Redis 的接口，底层基于 fjall 开发
Documentation 
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use crate::key_composer::{KeyComposer, KeyTag, SmallKey, encode_oppv_u64};

/// 栈上定长构造 Stream 元数据键（零堆分配）
#[inline]
pub fn meta(kc: &KeyComposer<'_>, key: &[u8]) -> SmallKey {
  kc.compose_meta_key_stack(KeyTag::StreamMeta.as_slice(), key)
}

/// 栈上定长构造 Stream 消息数据项存储键（零堆分配，大端序紧凑保序 16 字节）
#[inline]
pub fn item(kc: &KeyComposer<'_>, key: &[u8], ms: u64, seq: u64) -> SmallKey {
  kc.compose_subkey2_stack(
    KeyTag::StreamData.as_slice(),
    key,
    &ms.to_be_bytes(),
    &seq.to_be_bytes(),
  )
}

/// 构造 Stream 数据前缀
#[inline]
pub fn prefix(kc: &KeyComposer<'_>, key: &[u8]) -> Vec<u8> {
  kc.compose_prefix(KeyTag::StreamData.as_slice(), key)
}

/// 栈上定长构造 Stream 数据前缀（零堆分配）
#[inline]
pub fn prefix_stack(kc: &KeyComposer<'_>, key: &[u8]) -> SmallKey {
  kc.compose_prefix_stack(KeyTag::StreamData.as_slice(), key)
}

/// 栈上定长构造 Stream 消费者组元数据键（零堆分配）
#[inline]
pub fn group_meta(kc: &KeyComposer<'_>, key: &[u8], group: &[u8]) -> SmallKey {
  kc.compose_subkey_stack(KeyTag::StreamGroup.as_slice(), key, group)
}

/// 构造 Stream 消费者组前缀
#[inline]
pub fn group_prefix(kc: &KeyComposer<'_>, key: &[u8]) -> Vec<u8> {
  kc.compose_prefix(KeyTag::StreamGroup.as_slice(), key)
}

/// 栈上定长构造 Stream 消费者组前缀（零堆分配）
#[inline]
pub fn group_prefix_stack(kc: &KeyComposer<'_>, key: &[u8]) -> SmallKey {
  kc.compose_prefix_stack(KeyTag::StreamGroup.as_slice(), key)
}

/// 栈上定长构造 Stream 消费者元数据键（零堆分配）
#[inline]
pub fn consumer_meta(kc: &KeyComposer<'_>, key: &[u8], group: &[u8], consumer: &[u8]) -> SmallKey {
  kc.compose_oppv_subkey_stack(KeyTag::StreamConsumer.as_slice(), key, group, consumer)
}

/// 构造 Stream 消费者前缀（针对特定消费者组）
#[inline]
pub fn consumer_prefix(kc: &KeyComposer<'_>, key: &[u8], group: &[u8]) -> Vec<u8> {
  let mut buf = Vec::new();
  kc.compose_prefix_into_with_extra(
    KeyTag::StreamConsumer.as_slice(),
    key,
    9 + group.len(),
    &mut buf,
  );
  encode_oppv_u64(group.len() as u64, &mut buf);
  buf.extend_from_slice(group);
  buf
}

/// 构造 Stream 所有消费者前缀
#[inline]
pub fn consumer_prefix_all(kc: &KeyComposer<'_>, key: &[u8]) -> Vec<u8> {
  kc.compose_prefix(KeyTag::StreamConsumer.as_slice(), key)
}

/// 栈上定长构造 Stream PEL 项存储键（零堆分配，大端序紧凑保序 16 字节）
#[inline]
pub fn pel_item(kc: &KeyComposer<'_>, key: &[u8], group: &[u8], ms: u64, seq: u64) -> SmallKey {
  let mut id = [0u8; 16];
  id[..8].copy_from_slice(&ms.to_be_bytes());
  id[8..].copy_from_slice(&seq.to_be_bytes());
  kc.compose_oppv_subkey_stack(KeyTag::StreamPel.as_slice(), key, group, &id)
}

/// 构造 Stream PEL 前缀（针对特定消费者组）
#[inline]
pub fn pel_prefix(kc: &KeyComposer<'_>, key: &[u8], group: &[u8]) -> Vec<u8> {
  let mut buf = Vec::new();
  kc.compose_prefix_into_with_extra(KeyTag::StreamPel.as_slice(), key, 9 + group.len(), &mut buf);
  encode_oppv_u64(group.len() as u64, &mut buf);
  buf.extend_from_slice(group);
  buf
}

/// 构造 Stream 所有 PEL 前缀
#[inline]
pub fn pel_prefix_all(kc: &KeyComposer<'_>, key: &[u8]) -> Vec<u8> {
  kc.compose_prefix(KeyTag::StreamPel.as_slice(), key)
}