iridium_core 0.1.12

SQL Server-compatible Rust engine core for Iridium SQL
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152

use std::collections::HashMap;

use super::super::string_norm::normalize_identifier;
use super::types::{LockMode, SessionId, TableLockState};

/// Returned when a row lock acquisition triggers escalation.
pub(crate) struct EscalationRequest {
    pub table: String,
    pub mode: LockMode,
}

/// Manages row-level lock state and lock escalation.
pub(crate) struct RowLockManager {
    locks: HashMap<(String, usize), TableLockState>,
    lock_counts: HashMap<(SessionId, String), usize>,
    pub escalation_threshold: usize,
}

impl RowLockManager {
    pub fn new() -> Self {
        Self {
            locks: HashMap::new(),
            lock_counts: HashMap::new(),
            escalation_threshold: 5000,
        }
    }

    pub fn clear(&mut self) {
        self.locks.clear();
        self.lock_counts.clear();
    }

    pub fn can_acquire(
        &self,
        session_id: SessionId,
        table: &str,
        row_id: usize,
        mode: LockMode,
    ) -> bool {
        let normalized = normalize_identifier(table);
        let key = (normalized, row_id);
        match self.locks.get(&key) {
            Some(state) => !state.has_conflict(session_id, mode),
            None => true,
        }
    }

    /// Acquire a row lock. Returns an `EscalationRequest` if the threshold is reached.
    pub fn acquire(
        &mut self,
        session_id: SessionId,
        table: &str,
        row_id: usize,
        mode: LockMode,
    ) -> Option<EscalationRequest> {
        let normalized = normalize_identifier(table);
        let key = (normalized.clone(), row_id);
        self.locks.entry(key).or_default().acquire(session_id, mode);

        let count_key = (session_id, normalized.clone());
        let count = self.lock_counts.entry(count_key).or_insert(0);
        *count += 1;

        if *count >= self.escalation_threshold {
            Some(EscalationRequest {
                table: normalized,
                mode,
            })
        } else {
            None
        }
    }

    pub fn get_blocking_sessions(
        &self,
        session_id: SessionId,
        table: &str,
        row_id: usize,
        mode: LockMode,
    ) -> Vec<SessionId> {
        let normalized = normalize_identifier(table);
        let key = (normalized, row_id);
        match self.locks.get(&key) {
            Some(state) => state.collect_blockers(session_id, mode),
            None => Vec::new(),
        }
    }

    pub fn release_one(
        &mut self,
        session_id: SessionId,
        table: &str,
        row_id: usize,
        mode: LockMode,
    ) {
        let normalized = normalize_identifier(table);
        let key = (normalized.clone(), row_id);

        if let Some(state) = self.locks.get_mut(&key) {
            state.release_one(session_id, mode);
            if state.is_empty() {
                self.locks.remove(&key);
            }
        }

        let count_key = (session_id, normalized);
        if let Some(count) = self.lock_counts.get_mut(&count_key) {
            if *count > 1 {
                *count -= 1;
            } else {
                self.lock_counts.remove(&count_key);
            }
        }
    }

    pub fn release_all_for_session(&mut self, session_id: SessionId) {
        let row_keys: Vec<(String, usize)> = self.locks.keys().cloned().collect();
        for key in row_keys {
            if let Some(state) = self.locks.get_mut(&key) {
                state.release_all(session_id);
                if state.is_empty() {
                    self.locks.remove(&key);
                }
            }
        }
        self.lock_counts.retain(|(sid, _), _| *sid != session_id);
    }

    /// Perform escalation: remove all row locks for this session+table.
    /// The caller is responsible for adding the table-level lock.
    pub fn escalate_remove_rows(&mut self, session_id: SessionId, table: &str) {
        let normalized = normalize_identifier(table);

        let row_keys: Vec<(String, usize)> = self
            .locks
            .keys()
            .filter(|(t, _)| *t == normalized)
            .cloned()
            .collect();

        for key in row_keys {
            if let Some(state) = self.locks.get_mut(&key) {
                state.release_all(session_id);
                if state.is_empty() {
                    self.locks.remove(&key);
                }
            }
        }

        self.lock_counts.remove(&(session_id, normalized));
    }
}