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
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
use file_mmap::FileMmap;

#[derive(Clone,Copy,Default)]
pub struct DataAddress{
    offset:i64
    ,len:u64
}
impl DataAddress{
    pub fn offset(&self)->i64{
        self.offset
    }
    pub fn len(&self)->u64{
        self.len
    }
}
pub struct Data<'a>{
    address:DataAddress
    ,set:&'a VariousDataFile
}
impl Data<'_>{
    pub fn slice(&self)->&[u8]{
        self.set.slice(&self.address)
    }
    pub fn address(&self)->DataAddress{
        self.address
    }
}

pub struct VariousDataFile{
    filemmap:FileMmap
    ,fragment:Fragment
}
impl VariousDataFile{
    pub fn new(path:&str) -> Result<VariousDataFile,std::io::Error>{
        let filemmap=FileMmap::new(path,1)?;
        let fragment=Fragment::new(&(path.to_string()+".f"))?;
        Ok(VariousDataFile{
            filemmap
            ,fragment
        })
    }
    pub fn slice(&self,word:&DataAddress)->&[u8] {
        self.filemmap.slice(word.offset() as isize,word.len as usize)
    }
    pub fn offset(&self,addr:isize)->*const i8{
        self.filemmap.offset(addr)
    }
    pub fn insert(&mut self,target:&[u8])->Option<Data>{
        let len=target.len() as u64;
        match self.fragment.search_blank(len){
            Some(r)=>{
                self.filemmap.write(r.string_addr,target);
                self.fragment.release(r.fragment_id,len);
                Some(Data{
                    address:DataAddress{offset:r.string_addr as i64,len}
                    ,set:self
                })
            }
            ,None=>{
                if let Some(addr)=self.filemmap.append(target){
                    Some(Data{
                        address:DataAddress{offset:addr as i64,len}
                        ,set:self
                    })
                }else{
                    None
                }
            }
        }
    }
    pub fn remove(&mut self,ystr:&DataAddress){
        self.filemmap.write_0(ystr.offset as isize,ystr.len);
        self.fragment.insert(ystr).unwrap();
    }
}

struct FragmentGetResult{
    fragment_id:u64
    ,string_addr:u64
}
struct Fragment{
    filemmap:FileMmap
    ,list: Vec<DataAddress>
    ,record_count:u64
}
impl Fragment{
    pub fn new(path:&str) -> Result<Fragment,std::io::Error>{
        let init_size=std::mem::size_of::<DataAddress>() as u64;
        let filemmap=FileMmap::new(path,init_size)?;
        let list=filemmap.as_ptr() as *mut DataAddress;
        let len=filemmap.len() as u64;
        let mut record_count=if len==init_size{
            0
        }else{
            (len-init_size)/std::mem::size_of::<DataAddress>() as u64 - 1
        };
        if record_count>0{
            for i in -(record_count as i64)..0{
                let index=(-i) as u64;
                if unsafe{*list.offset(index as isize)}.offset==0{
                    record_count=index-1;
                }
            }
        }
        Ok(Fragment{
            filemmap
            ,list:unsafe{Vec::from_raw_parts(list,1,0)}
            ,record_count
        })
    }
    pub fn insert(&mut self,ystr:&DataAddress)->Result<u64,std::io::Error>{
        self.record_count+=1;
        let size=
            (std::mem::size_of::<DataAddress>() as u64)*(1+self.record_count)
        ;
        if self.filemmap.len()<size{
            self.filemmap.set_len(size as u64)?;
        }
        unsafe{
            *(self.list.as_ptr() as *mut DataAddress).offset(self.record_count as isize)=*ystr;
        }
        Ok(self.record_count)
    }
    pub fn release(&mut self,row:u64,len:u64){
        let mut s=&mut unsafe{
            *(self.list.as_ptr() as *mut DataAddress).offset(row as isize)
        };
        s.offset+=len as i64;
        s.len-=len;

        if s.len==0 && row==self.record_count{
            self.record_count-=1;
        }
    }
    pub fn search_blank(&self,len:u64)->Option<FragmentGetResult>{
        if self.record_count==0{
            None
        }else{
            for i in -(self.record_count as i64)..0{
                let index=(-i) as u64;
                let s=&mut unsafe{
                    *(self.list.as_ptr() as *mut DataAddress).offset(index as isize)
                };
                if s.len>=len{
                    return Some(FragmentGetResult{
                        fragment_id:index
                        ,string_addr:s.offset as u64
                    });
                }
            }
            None
        }
    }
}


#[test]
fn test(){
    if let Ok(mut s)=VariousDataFile::new("D:\\test.str"){
        if let Some(w)=s.insert(b"TEST"){
            assert_eq!("TEST".to_string(),std::str::from_utf8(w.slice()).unwrap().to_string());
        }
        if let Some(w)=s.insert(b"HOGE"){
            assert_eq!("HOGE".to_string(),std::str::from_utf8(w.slice()).unwrap().to_string());
        }
        if let Some(w)=s.insert(b"TEST"){
            assert_eq!("TEST".to_string(),std::str::from_utf8(w.slice()).unwrap().to_string());
        }
    }
}