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

use PersyId;
use persy::{PersyImpl};
use transaction::Transaction;
use segment::{SegmentScanner, SegmentIterator};
use std::iter::Chain;
use transaction::TransactionInsertIterator;

/// IntoIterator of persistent records of a segment
pub struct RecordScanner<'a> {
    persy: &'a PersyImpl,
    segment_id: u32,
    scanner: SegmentScanner<'a>,
}

pub struct RecordIterator<'a> {
    persy: &'a PersyImpl,
    segment_id: u32,
    iterator: SegmentIterator<'a>,
}

/// Snapshot of a record from the segment iterator
pub struct IteratorItem {
    /// Identifier of the record can be used for do update or delete.
    ///
    pub id: PersyId,
    /// Content of the record
    ///
    pub content: Vec<u8>,
}

impl<'a> RecordScanner<'a> {
    pub fn new<'b>(persy: &'b PersyImpl, segment_id: u32, scanner: SegmentScanner<'b>) -> RecordScanner<'b> {
        RecordScanner::<'b> {
            persy: persy,
            segment_id: segment_id,
            scanner: scanner,
        }
    }
}

impl<'a> IntoIterator for RecordScanner<'a> {
    type Item = IteratorItem;
    type IntoIter = RecordIterator<'a>;

    fn into_iter(self) -> Self::IntoIter {
        RecordIterator::<'a> {
            persy: self.persy,
            segment_id: self.segment_id,
            iterator: self.scanner.into_iter(),
        }
    }
}

impl<'a> Iterator for RecordIterator<'a> {
    type Item = IteratorItem;
    fn next(&mut self) -> Option<Self::Item> {
        let rec;
        loop {
            let iter = self.iterator.next();
            if let Some(id) = iter {
                let res = self.persy.read_record_scan(self.segment_id, &id);
                if !res.is_err() {
                    let tp = res.unwrap();
                    if let Some(val) = tp {
                        rec = Some(IteratorItem {
                            id: id,
                            content: val,
                        });
                        break;
                    }
                }
            } else {
                rec = None;
                break;
            }
        }

        rec
    }
}

/// IntoIterator of persistent records of a segment that include eventual in transaction changes
pub struct RecordScannerTx<'a> {
    persy: &'a PersyImpl,
    segment_id: u32,
    scanner: SegmentScanner<'a>,
    tx: &'a Transaction,
}

pub struct RecordIteratorTx<'a> {
    persy: &'a PersyImpl,
    segment_id: u32,
    iterator: Chain<TransactionInsertIterator, SegmentIterator<'a>>,
    tx: &'a Transaction,
}

impl<'a> RecordScannerTx<'a> {
    pub fn new<'b>(persy: &'b PersyImpl, tx: &'b Transaction, segment_id: u32, scanner: SegmentScanner<'b>) -> RecordScannerTx<'b> {
        RecordScannerTx::<'b> {
            persy: persy,
            segment_id: segment_id,
            scanner: scanner,
            tx: tx,
        }
    }
}

impl<'a> IntoIterator for RecordScannerTx<'a> {
    type Item = IteratorItem;
    type IntoIter = RecordIteratorTx<'a>;

    fn into_iter(self) -> Self::IntoIter {
        let iter = self.tx.scan_insert(self.segment_id).into_iter().chain(self.scanner.into_iter());
        RecordIteratorTx::<'a> {
            persy: self.persy,
            segment_id: self.segment_id,
            iterator: iter,
            tx: self.tx,
        }
    }
}

impl<'a> Iterator for RecordIteratorTx<'a> {
    type Item = IteratorItem;
    fn next(&mut self) -> Option<Self::Item> {
        let rec;
        loop {
            let iter = self.iterator.next();
            if let Some(id) = iter {
                let res = self.persy.read_record_scan_tx(&self.tx, self.segment_id, &id);
                if !res.is_err() {
                    let tp = res.unwrap();
                    if let Some(val) = tp {
                        rec = Some(IteratorItem {
                            id: id.clone(),
                            content: val,
                        });
                        break;
                    }
                }
            } else {
                rec = None;
                break;
            }
        }

        rec
    }
}