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Runtime error
Runtime error
File size: 2,133 Bytes
b3b8f74 | 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 | import Stream from 'stream'
export default function largeObject(sql, oid, mode = 0x00020000 | 0x00040000) {
return new Promise(async(resolve, reject) => {
await sql.begin(async sql => {
let finish
!oid && ([{ oid }] = await sql`select lo_creat(-1) as oid`)
const [{ fd }] = await sql`select lo_open(${ oid }, ${ mode }) as fd`
const lo = {
writable,
readable,
close : () => sql`select lo_close(${ fd })`.then(finish),
tell : () => sql`select lo_tell64(${ fd })`,
read : (x) => sql`select loread(${ fd }, ${ x }) as data`,
write : (x) => sql`select lowrite(${ fd }, ${ x })`,
truncate : (x) => sql`select lo_truncate64(${ fd }, ${ x })`,
seek : (x, whence = 0) => sql`select lo_lseek64(${ fd }, ${ x }, ${ whence })`,
size : () => sql`
select
lo_lseek64(${ fd }, location, 0) as position,
seek.size
from (
select
lo_lseek64($1, 0, 2) as size,
tell.location
from (select lo_tell64($1) as location) tell
) seek
`
}
resolve(lo)
return new Promise(async r => finish = r)
async function readable({
highWaterMark = 2048 * 8,
start = 0,
end = Infinity
} = {}) {
let max = end - start
start && await lo.seek(start)
return new Stream.Readable({
highWaterMark,
async read(size) {
const l = size > max ? size - max : size
max -= size
const [{ data }] = await lo.read(l)
this.push(data)
if (data.length < size)
this.push(null)
}
})
}
async function writable({
highWaterMark = 2048 * 8,
start = 0
} = {}) {
start && await lo.seek(start)
return new Stream.Writable({
highWaterMark,
write(chunk, encoding, callback) {
lo.write(chunk).then(() => callback(), callback)
}
})
}
}).catch(reject)
})
}
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