An arduino library implementing a ring buffer especially designed for strings.

To use the library, you must first construct an object of type StrRingBuffer. Then you can use any of the methods displayed below.

The constructor takes an optional single argument which is the size of the ring buffer. By default, the size will be STRRINGBUFFER_DEF_SIZE, which is a define in strringbuffer.h. The default value is equal to 16, but if you want to change it, you can define it to a different value before including the header file.

The destructor just frees up the allocated memory.

The reset method resets all internal pointers and provides a fresh ring buffer.

The buflen method returns the length of the buffer.

The strlen method returns the length of the string stored inside the buffer.

The push method appends the character c to the buffer.

The pop method returns the first character from the buffer. Since it is a ring buffer, it is a FIFO and not a LIFO queue. The character will be deleted from the buffer.

The peek method returns the first character from the buffer, without removing it.

The getstr method copies the string stored in the buffer to target. It is up to the user to provide a large enough string to hold all the contents of the buffer. At the end of the string, a \0 will be appended.

Similar to getstr, getnstr copies the string stored in the buffer to target, but will store a maximum of len characters, including the final \0.

The pushstr method will append all characters from s to the buffer.

The pushnstr method will append at most len characters from s to the buffer. If the string stored in s is less than len characters then the whole string will be appended.

The strcmp method compares the string from the buffer with str. The return value is similar to the result of using the standard strcmp function to compare the string stored in the buffer and str.

Similar to strcmp, but compares at most len characters. Similar to using the standard strncmp function.

The endswith method returns true if the buffer ends with str, otherwise false.

The endsnwith method returns true if the buffer ends with at most len characters from str, otherwise false.

You can find sample code in the examples/ directory.

It is important to note that since the library was designed to be small and fast, there are several things that are missing.

The most important thing is that there is no buffer overflow detection and protection. Thus, if you have a buffer which can hold a maximum of 16 characters, the library will not stop you from inserting 20 characters or a 20 character string. It is up to you to reserve the appropriate buffer.

Futhermore, a buffer with a size equal to n can hold up to n - 1 characters. This was a design decision, since adding the necessary checks would require a more memory and more code.

The code is licensed under the BSD 3-clause "New" or "Revised" License.