![]() Most languages will provide a fixed size buffer for performance reasons, and then provide another version that is dynamic in size. The file system simply allocates another node and keeps all the nodes linked together, and when you read from it the complexity is abstracted away so that the file/buffer appears to be a single contiguous buffer.įor those of you who wish to understand the difficulty in just simply providing a high performance dynamic buffer you only need to view the code below, and also do some research on memory heap algorithms and how the memory heap works for programs. This is essentially how most file systems handle writing data to a file. Therefore most applications when needing to store a unknown amount of data will use a method like below and not constantly reallocate, unless the reallocation is very infrequent. The realloc function in C (or any language dealing with intrinsic allocations) does not guarantee that the allocation will be expanded in size with out moving the existing data - although sometimes it is possible. I have left the read method unimplemented to keep the example small in size. The code below may have potential to be optimized further. By understanding why the problem exists and how to solve it you will improve your ability to solve other problems in the future since this one is so fundamental.įor those of us that have to deal with these problems in other languages it is quite natural to devise a solution, but there are people who may not realize how to abstract away the complexities and implement a generally efficient dynamic buffer. I would recommend understanding this problem because it can happen in lots of different places not just with a JS Buffer object. This is to help anyone who comes here looking for a solution that wants a pure approach. The BufferedWriter appends content to the end of the file because append = true Same as BufferedReader but for writing.Ī quick example: //The BufferedWriter truncates the file because append = false I've written a BufferedWriter that writes bytes to a file using internal buffers. New Buffer ().copy (b) īut this seems a bit inefficient because I have to instantiate a new buffer for every append.ĭo you know a better way for appending binary data? Then, the only solution I can see here is to create a new buffer for every appended binary data and copy it to the major buffer with the correct offset: var b = new Buffer (4) //4 for having a nice printed buffer, but the size will be 16KB How can I append more binary data? I'm searching in the documentation but for appending data it must be a string, if not, an error occurs ( TypeError: Argument must be a string): var b = new Buffer (256) Ĭonsole.log (b.toString ("utf8", 0, 4)) //holaĬonsole.log (b.toString ("utf8", 0, 11)) //hola, adios I have a buffer with some binary data: var b = new Buffer ()
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