Description Usage Arguments Value See Also Examples
Get a mongo.cursor for a range of chunks in a mongo.gridfile.
1 | mongo.gridfile.get.chunks(gridfile, start, count)
|
gridfile |
A (mongo.gridfile) object. |
start |
(integer) The index of the first chunk to fetch. This should
be in the range 0 to |
count |
(integer) The number of chunks to fetch. |
(mongo.cursor) A cursor to be used to step through the requested chunks.
The values returned by mongo.cursor.value()
will be
consecutive documents in the 'chunks' collection of the GridFS. The 'data'
field of these documents contains the actual data belonging to the chunk.
See http://www.mongodb.org/display/DOCS/GridFS+Specification.
mongo.gridfs
,
mongo.gridfs.find
,
mongo.gridfile,
mongo.gridfile.get.descriptor
,
mongo.gridfile.get.filename
,
mongo.gridfile.get.length
,
mongo.gridfile.get.chunk.size
,
mongo.gridfile.get.chunk.count
,
mongo.gridfile.get.content.type
,
mongo.gridfile.get.upload.date
,
mongo.gridfile.get.md5
,
mongo.gridfile.get.metadata
,
mongo.gridfile.get.chunk
,
mongo.gridfile.read
,
mongo.gridfile.seek
,
mongo.gridfile.pipe
.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 | mongo <- mongo.create()
if (mongo.is.connected(mongo)) {
gridfs <- mongo.gridfs.create(mongo, "grid")
mongo.gridfs.store.file(gridfs, "tests/test.R", "test.R")
gf <- mongo.gridfs.find(gridfs, "test.R")
if( !is.null(gf)){
cursor <- mongo.gridfile.get.chunks(gf, 1, 2)
f <- file("rmongodb.pdf.chunks12", "wb")
while (mongo.cursor.next(cursor)) {
chunk <- mongo.cursor.value(cursor)
iter <- mongo.bson.find(chunk, "data")
# write the binary (raw) data to the file
writeBin(mongo.bson.iterator.value(iter), f)
}
close(f)
mongo.gridfile.destroy(gf)
}
mongo.gridfs.destroy(gridfs)
}
|
Add the following code to your website.
For more information on customizing the embed code, read Embedding Snippets.