SparkFunESP8266ClientReadBuffer.cpp

#include "SparkFunESP8266ClientReadBuffer.h"
#include "SparkFunESP8266WiFi.h"



int ESP8266ClientReadBuffer::available()
{
	if (receiveBufferSize > 0)//client has already buffered some payload
		return receiveBufferSize;

	int available = esp8266.available();
	if (available == 0)
	{
		// Delay for the amount of time it'd take to receive one character
		delayMicroseconds((1 / esp8266._baud) * 10 * 1E6);
		// Check again just to be sure:
		available = esp8266.available();
	}
	return available;
}

int ESP8266ClientReadBuffer::read()
{
	this->fillReceiveBuffer();//append to buffer BEFORE we read, so that chances are higher to detect AT commands

	//read from buffer
	if (receiveBufferSize > 0) {
		uint8_t ret = receiveBuffer[0];
		this->truncateReceiveBufferHead(0, 1);
		return ret;
	}

	return -1;
}

void ESP8266ClientReadBuffer::truncateReceiveBufferHead(uint8_t startingOffset, uint8_t truncateLength) {
	for (uint8_t i = startingOffset; i < receiveBufferSize - truncateLength; i++)//shift buffer content; todo: better implementation
		receiveBuffer[i] = receiveBuffer[i + truncateLength];
	receiveBufferSize -= truncateLength;
}

void ESP8266ClientReadBuffer::fillReceiveBuffer() {
	//fill the receive buffer as much as possible from esp8266.read()

	for (uint8_t attemps = 0; attemps < 5; attemps++) {//often 1st available() call does not yield all bytes => outer while
		while (uint8_t availableBytes = esp8266.available() > 0) {
			for (; availableBytes > 0 && receiveBufferSize < ESP8266_CLIENT_MAX_BUFFER_SIZE; availableBytes--) {
				receiveBuffer[receiveBufferSize++] = esp8266.read();
			}
			delay(10);
		}
		delay(10);
	}

	this->cleanReceiveBufferFromAT();
}

void ESP8266ClientReadBuffer::cleanReceiveBufferFromAT() {
	//get rid of these esp8266 commands
	this->cleanReceiveBufferFromAT("\r\n\r\n+IPD", 5);//typical answer looks like \r\n\r\n+IPD,0,4:<payload>
}

void ESP8266ClientReadBuffer::cleanReceiveBufferFromAT(const char *atCommand, uint8_t additionalSuffixToKill) {
	uint8_t atLen = strlen(atCommand);

	//uint8_t offset = 0;
	for (uint8_t offset = 0; offset <= receiveBufferSize - atLen; offset++) {
		if (0 == memcmp((receiveBuffer + offset), atCommand, atLen)) {
			//found the at command. KILL IT!
			this->truncateReceiveBufferHead(offset, atLen + additionalSuffixToKill);
			break;
		}
	}
}