Net reading file stream

The byte offset is relative to the seek reference point, which can be the beginning, the current position, or the end of the underlying file, as represented by the three members of the SeekOrigin enumeration. Disk files always support random access.

At the time of construction, the CanSeek property value is set to true or false depending on the underlying file type. Otherwise, the CanSeek property value is false.

If a process terminates with part of a file locked or closes a file that has outstanding locks, the behavior is undefined. For directory operations and other file operations, see the File , Directory , and Path classes.

The File class is a utility class that has static methods primarily for the creation of FileStream objects based on file paths. The MemoryStream class creates a stream from a byte array and is similar to the FileStream class. When a FileStream object does not have an exclusive hold on its handle, another thread could access the file handle concurrently and change the position of the operating system's file pointer that is associated with the file handle.

In this case, the cached position in the FileStream object and the cached data in the buffer could be compromised. The FileStream object routinely performs checks on methods that access the cached buffer to ensure that the operating system's handle position is the same as the cached position used by the FileStream object.

If an unexpected change in the handle position is detected in a call to the Read method, the. NET Framework discards the contents of the buffer and reads the stream from the file again.

This can affect performance, depending on the size of the file and any other processes that could affect the position of the file stream. If an unexpected change in the handle position is detected in a call to the Write method, the contents of the buffer are discarded and an IOException exception is thrown. A FileStream object will not have an exclusive hold on its handle when either the SafeFileHandle property is accessed to expose the handle or the FileStream object is given the SafeFileHandle property in its constructor.

Initializes a new instance of the FileStream class with the specified path and creation mode. Initializes a new instance of the FileStream class with the specified path, creation mode, access rights and sharing permission, the buffer size, and additional file options. Initializes a new instance of the FileStream class with the specified path, creation mode, access rights and sharing permission, the buffer size, additional file options, access control and audit security.

Gets the operating system file handle for the file that the current FileStream object encapsulates. Gets a value that indicates whether the FileStream was opened asynchronously or synchronously. Gets the absolute path of the file opened in the FileStream. Gets or sets a value, in milliseconds, that determines how long the stream will attempt to read before timing out.

Gets a SafeFileHandle object that represents the operating system file handle for the file that the current FileStream object encapsulates. Gets or sets a value, in milliseconds, that determines how long the stream will attempt to write before timing out. Begins an asynchronous read operation. Begins an asynchronous write operation. Closes the current stream and releases any resources such as sockets and file handles associated with the current stream.

Instead of calling this method, ensure that the stream is properly disposed. Reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified cancellation token. Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size. Asynchronously reads the bytes from the current file stream and writes them to another stream, using a specified buffer size and cancellation token.

Asynchronously reads the bytes from the current stream and writes them to another stream, using a specified buffer size and cancellation token. Creates an object that contains all the relevant information required to generate a proxy used to communicate with a remote object. Whilst the most upvoted answer is correct but it lacks usage of multi-core processing.

In my case, having 12 cores I use PLink:. NET Framework 4. As the file is loaded, the iterator will return the progress number from 0 to , which you can use to update your progress bar. Once the loop has finished, the StringBuilder will contain the contents of the text file. Also, because you want text, we can just use BinaryReader to read in characters, which will ensure that your buffers line up correctly when reading any multi-byte characters UTF-8 , UTF , etc.

My file is over 13 GB:. More information. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams? Collectives on Stack Overflow. Learn more. Reading large text files with streams in C Ask Question. Asked 11 years, 11 months ago. Active 11 months ago. Viewed k times. The developer who wrote the initial code is simply using a StreamReader and doing [Reader].

ReadToEnd which could take quite a while to complete. Once the contents is retrieved we work out what terminator is used. No-one's concerned once it's loaded the time it takes to render in the richtextbox. It's just the initial load of the text. Then return the stringbuilder to the main thread once it's completed. The contents will be going to a StringBuilder. Peter Mortensen Nicole Lee Nicole Lee 1, 2 2 gold badges 8 8 silver badges 4 4 bronze badges.

Holy mackerel! I'd hate to have to code review that I know this questions is rather old but I found it the other day and have tested the recommendation for MemoryMappedFile and this is hands down the fastest method. It's just few lines of code. See this library I am using to read 25gb and more large files as well. Add a comment.

Active Oldest Votes. Open path, FileMode. Open, FileAccess. Read, FileShare. Why BufferedStream is faster A buffer is a block of bytes in memory used to cache data, thereby reducing the number of calls to the operating system.

Community Bot 1 1 1 silver badge. Eric J. Dude, BufferedStream makes all the difference. There is a cost to requesting data from an IO subsystem. In the case of rotating disks, you might have to wait for the platter to spin into position to read the next chunk of data, or worse, wait for the disk head to move. While SSD's don't have mechanical parts to slow things down, there is still a per-IO-operation cost to access them. NET for desktop apps. In both examples, when you create the instance of the StreamReader class, you provide the relative or absolute path to the file.

These code examples do not apply to Universal Windows UWP apps, because the Windows Runtime provides different stream types for reading and writing to files. For an example that shows how to read text from a file in a UWP app, see Quickstart: Reading and writing files. For examples that show how to convert between. The following example shows a synchronous read operation within a console app. What my goal is, is to be able to read the objects from the stream one at a time.

Read an object, do something with it, then discard it from RAM, and read the next object, and so on. This should resolve your problem. I think we can do better than the accepted answer, using more features of JsonReader to make a more generalized solution. Path property. We can use this to precisely select deeply nested data from a JSON file, using regex to ensure that we're on the right path. I've found this technique extremely useful for extracting specific data from huge GiB JSON dumps, directly from HTTP using a network stream with low memory requirements and no intermediate storage required.

NET under the hood to parse the json in stream manner. Is this what you're looking for? Found on a previous question. The current version of Json. A current alternative is:. Stack Overflow for Teams — Collaborate and share knowledge with a private group. Create a free Team What is Teams?

Collectives on Stack Overflow. Learn more. Ask Question. Asked 4 years, 8 months ago. Active 3 months ago.