Class: XGen::Mongo::GridFS::GridStore
- Inherits:
-
Object
- Object
- XGen::Mongo::GridFS::GridStore
- Includes:
- Enumerable
- Defined in:
- lib/mongo/gridfs/grid_store.rb
Overview
GridStore is an IO-like object that provides input and output for streams of data to Mongo. See Mongo’s documentation about GridFS for storage implementation details.
Example code:
require 'mongo/gridfs'
GridStore.open(database, 'filename', 'w') { |f|
f.puts "Hello, world!"
}
GridStore.open(database, 'filename, 'r') { |f|
puts f.read # => Hello, world!\n
}
GridStore.open(database, 'filename', 'w+') { |f|
f.puts "But wait, there's more!"
}
GridStore.open(database, 'filename, 'r') { |f|
puts f.read # => Hello, world!\nBut wait, there's more!\n
}
Constant Summary collapse
- DEFAULT_ROOT_COLLECTION =
'fs'
- DEFAULT_CONTENT_TYPE =
'text/plain'
Instance Attribute Summary collapse
-
#aliases ⇒ Object
Array of strings; may be
nil
. -
#chunk_size ⇒ Object
Returns the value of attribute chunk_size.
-
#content_type ⇒ Object
Default is DEFAULT_CONTENT_TYPE.
-
#filename ⇒ Object
Returns the value of attribute filename.
-
#files_id ⇒ Object
readonly
Returns the value of attribute files_id.
-
#lineno ⇒ Object
Returns the value of attribute lineno.
-
#md5 ⇒ Object
readonly
Returns the value of attribute md5.
-
#metadata ⇒ Object
Returns the value of attribute metadata.
-
#upload_date ⇒ Object
readonly
Time that the file was first saved.
Class Method Summary collapse
- .exist?(db, name, root_collection = DEFAULT_ROOT_COLLECTION) ⇒ Boolean
- .open(db, name, mode, options = {}) ⇒ Object
- .read(db, name, length = nil, offset = nil) ⇒ Object
- .readlines(db, name, separator = $/) ⇒ Object
- .unlink(db, *names) ⇒ Object (also: delete)
Instance Method Summary collapse
- #<<(obj) ⇒ Object
-
#chunk_collection ⇒ Object
Returns collection used for storing chunks.
-
#close ⇒ Object
— ================ closing ================ +++.
- #closed? ⇒ Boolean
- #collection ⇒ Object
- #each ⇒ Object (also: #each_line)
- #each_byte ⇒ Object
-
#eof ⇒ Object
(also: #eof?)
— ================ status ================ +++.
-
#flush ⇒ Object
A no-op.
-
#getc ⇒ Object
— ================ reading ================ +++.
- #gets(separator = $/) ⇒ Object
-
#initialize(db, name, mode = 'r', options = {}) ⇒ GridStore
constructor
Mode may only be ‘r’, ‘w’, or ‘w+’.
- #print(*objs) ⇒ Object
-
#putc(byte) ⇒ Object
— ================ writing ================ +++.
- #puts(*objs) ⇒ Object
- #read(len = nil, buf = nil) ⇒ Object
- #readchar ⇒ Object
- #readline(separator = $/) ⇒ Object
- #readlines(separator = $/) ⇒ Object
-
#rewind ⇒ Object
— ================ positioning ================ +++.
- #seek(pos, whence = IO::SEEK_SET) ⇒ Object
- #tell ⇒ Object
- #ungetc(byte) ⇒ Object
-
#write(string) ⇒ Object
Writes
string
as bytes and returns the number of bytes written.
Constructor Details
#initialize(db, name, mode = 'r', options = {}) ⇒ GridStore
Mode may only be ‘r’, ‘w’, or ‘w+’.
Options. Descriptions start with a list of the modes for which that option is legitimate.
- :root
-
(r, w, w+) Name of root collection to use, instead of DEFAULT_ROOT_COLLECTION.
- :metadata
-
(w, w+) A hash containing any data you want persisted as
this file's metadata. See also metadata=
- :chunk_size
-
(w) Sets chunk size for files opened for writing See also chunk_size= which may only be called before any data is written.
- :content_type
-
(w) Default value is DEFAULT_CONTENT_TYPE. See also #content_type=
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# File 'lib/mongo/gridfs/grid_store.rb', line 134 def initialize(db, name, mode='r', ={}) @db, @filename, @mode = db, name, mode @root = [:root] || DEFAULT_ROOT_COLLECTION doc = collection.find({'filename' => @filename}).next_object if doc @files_id = doc['_id'] @content_type = doc['contentType'] @chunk_size = doc['chunkSize'] @upload_date = doc['uploadDate'] @aliases = doc['aliases'] @length = doc['length'] @metadata = doc['metadata'] @md5 = doc['md5'] else @files_id = XGen::Mongo::Driver::ObjectID.new @content_type = DEFAULT_CONTENT_TYPE @chunk_size = Chunk::DEFAULT_CHUNK_SIZE @length = 0 end case mode when 'r' @curr_chunk = nth_chunk(0) @position = 0 when 'w' chunk_collection.create_index([['files_id', XGen::Mongo::ASCENDING], ['n', XGen::Mongo::ASCENDING]]) delete_chunks @curr_chunk = Chunk.new(self, 'n' => 0) @content_type = [:content_type] if [:content_type] @chunk_size = [:chunk_size] if [:chunk_size] @metadata = [:metadata] if [:metadata] @position = 0 when 'w+' chunk_collection.create_index([['files_id', XGen::Mongo::ASCENDING], ['n', XGen::Mongo::ASCENDING]]) @curr_chunk = nth_chunk(last_chunk_number) || Chunk.new(self, 'n' => 0) # might be empty @curr_chunk.pos = @curr_chunk.data.length if @curr_chunk @metadata = [:metadata] if [:metadata] @position = @length else raise "error: illegal mode #{mode}" end @lineno = 0 @pushback_byte = nil end |
Instance Attribute Details
#aliases ⇒ Object
Array of strings; may be nil
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# File 'lib/mongo/gridfs/grid_store.rb', line 54 def aliases @aliases end |
#chunk_size ⇒ Object
Returns the value of attribute chunk_size.
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# File 'lib/mongo/gridfs/grid_store.rb', line 66 def chunk_size @chunk_size end |
#content_type ⇒ Object
Default is DEFAULT_CONTENT_TYPE
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# File 'lib/mongo/gridfs/grid_store.rb', line 57 def content_type @content_type end |
#filename ⇒ Object
Returns the value of attribute filename.
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# File 'lib/mongo/gridfs/grid_store.rb', line 51 def filename @filename end |
#files_id ⇒ Object (readonly)
Returns the value of attribute files_id.
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# File 'lib/mongo/gridfs/grid_store.rb', line 61 def files_id @files_id end |
#lineno ⇒ Object
Returns the value of attribute lineno.
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# File 'lib/mongo/gridfs/grid_store.rb', line 68 def lineno @lineno end |
#md5 ⇒ Object (readonly)
Returns the value of attribute md5.
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# File 'lib/mongo/gridfs/grid_store.rb', line 70 def md5 @md5 end |
#metadata ⇒ Object
Returns the value of attribute metadata.
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# File 'lib/mongo/gridfs/grid_store.rb', line 59 def @metadata end |
#upload_date ⇒ Object (readonly)
Time that the file was first saved.
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# File 'lib/mongo/gridfs/grid_store.rb', line 64 def upload_date @upload_date end |
Class Method Details
.exist?(db, name, root_collection = DEFAULT_ROOT_COLLECTION) ⇒ Boolean
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# File 'lib/mongo/gridfs/grid_store.rb', line 74 def exist?(db, name, root_collection=DEFAULT_ROOT_COLLECTION) db.collection("#{root_collection}.files").find({'filename' => name}).next_object != nil end |
.open(db, name, mode, options = {}) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 78 def open(db, name, mode, ={}) gs = self.new(db, name, mode, ) result = nil begin result = yield gs if block_given? ensure gs.close end result end |
.read(db, name, length = nil, offset = nil) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 89 def read(db, name, length=nil, offset=nil) GridStore.open(db, name, 'r') { |gs| gs.seek(offset) if offset gs.read(length) } end |
Instance Method Details
#<<(obj) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 320 def <<(obj) write(obj.to_s) end |
#chunk_collection ⇒ Object
Returns collection used for storing chunks. Depends on value of
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# File 'lib/mongo/gridfs/grid_store.rb', line 187 def chunk_collection @db.collection("#{@root}.chunks") end |
#close ⇒ Object
closing ================
+++
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# File 'lib/mongo/gridfs/grid_store.rb', line 395 def close if @mode[0] == ?w if @curr_chunk @curr_chunk.truncate @curr_chunk.save if @curr_chunk.pos > 0 end files = collection if @upload_date files.remove('_id' => @files_id) else @upload_date = Time.now end files.insert(to_mongo_object) end @db = nil end |
#closed? ⇒ Boolean
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# File 'lib/mongo/gridfs/grid_store.rb', line 412 def closed? @db == nil end |
#collection ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 181 def collection @db.collection("#{@root}.files") end |
#each ⇒ Object Also known as: each_line
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# File 'lib/mongo/gridfs/grid_store.rb', line 262 def each line = gets while line yield line line = gets end end |
#each_byte ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 271 def each_byte byte = self.getc while byte yield byte byte = self.getc end end |
#eof ⇒ Object Also known as: eof?
status ================
+++
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# File 'lib/mongo/gridfs/grid_store.rb', line 343 def eof raise IOError.new("stream not open for reading") unless @mode[0] == ?r @position >= @length end |
#flush ⇒ Object
A no-op.
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# File 'lib/mongo/gridfs/grid_store.rb', line 336 def flush end |
#getc ⇒ Object
reading ================
+++
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# File 'lib/mongo/gridfs/grid_store.rb', line 204 def getc if @pushback_byte byte = @pushback_byte @pushback_byte = nil @position += 1 byte elsif eof? nil else if @curr_chunk.eof? @curr_chunk = nth_chunk(@curr_chunk.chunk_number + 1) end @position += 1 @curr_chunk.getc end end |
#gets(separator = $/) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 221 def gets(separator=$/) str = '' byte = self.getc return nil if byte == nil # EOF while byte != nil s = byte.chr str << s break if s == separator byte = self.getc end @lineno += 1 str end |
#print(*objs) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 298 def print(*objs) objs = [$_] if objs == nil || objs.empty? objs.each { |obj| str = obj.to_s str.each_byte { |byte| self.putc(byte) } } nil end |
#putc(byte) ⇒ Object
writing ================
+++
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# File 'lib/mongo/gridfs/grid_store.rb', line 288 def putc(byte) if @curr_chunk.pos == @chunk_size prev_chunk_number = @curr_chunk.chunk_number @curr_chunk.save @curr_chunk = Chunk.new(self, 'n' => prev_chunk_number + 1) end @position += 1 @curr_chunk.putc(byte) end |
#puts(*objs) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 307 def puts(*objs) if objs == nil || objs.empty? self.putc(10) else print(*objs.collect{ |obj| str = obj.to_s str << "\n" unless str =~ /\n$/ str }) end nil end |
#read(len = nil, buf = nil) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 235 def read(len=nil, buf=nil) buf ||= '' byte = self.getc while byte != nil && (len == nil || len > 0) buf << byte.chr len -= 1 if len byte = self.getc if (len == nil || len > 0) end buf end |
#readchar ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 246 def readchar byte = self.getc raise EOFError.new if byte == nil byte end |
#readline(separator = $/) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 252 def readline(separator=$/) line = gets raise EOFError.new if line == nil line end |
#readlines(separator = $/) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 258 def readlines(separator=$/) read.split(separator).collect { |line| "#{line}#{separator}" } end |
#rewind ⇒ Object
positioning ================
+++
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# File 'lib/mongo/gridfs/grid_store.rb', line 353 def rewind if @curr_chunk.chunk_number != 0 if @mode[0] == ?w delete_chunks @curr_chunk = Chunk.new(self, 'n' => 0) else @curr_chunk == nth_chunk(0) end end @curr_chunk.pos = 0 @lineno = 0 @position = 0 end |
#seek(pos, whence = IO::SEEK_SET) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 367 def seek(pos, whence=IO::SEEK_SET) target_pos = case whence when IO::SEEK_CUR @position + pos when IO::SEEK_END @length + pos when IO::SEEK_SET pos end new_chunk_number = (target_pos / @chunk_size).to_i if new_chunk_number != @curr_chunk.chunk_number @curr_chunk.save if @mode[0] == ?w @curr_chunk = nth_chunk(new_chunk_number) end @position = target_pos @curr_chunk.pos = @position % @chunk_size 0 end |
#tell ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 387 def tell @position end |
#ungetc(byte) ⇒ Object
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# File 'lib/mongo/gridfs/grid_store.rb', line 279 def ungetc(byte) @pushback_byte = byte @position -= 1 end |
#write(string) ⇒ Object
Writes string
as bytes and returns the number of bytes written.
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# File 'lib/mongo/gridfs/grid_store.rb', line 325 def write(string) raise "#@filename not opened for write" unless @mode[0] == ?w count = 0 string.each_byte { |byte| self.putc byte count += 1 } count end |