Thrift HTTP client in C++
Reviewed By: aditya, dweatherford
Test Plan: SMC client
git-svn-id: https://svn.apache.org/repos/asf/incubator/thrift/trunk@665022 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/lib/cpp/src/transport/THttpClient.cpp b/lib/cpp/src/transport/THttpClient.cpp
new file mode 100644
index 0000000..7ee83fc
--- /dev/null
+++ b/lib/cpp/src/transport/THttpClient.cpp
@@ -0,0 +1,318 @@
+#include "THttpClient.h"
+#include "TSocket.h"
+
+namespace facebook { namespace thrift { namespace transport {
+
+using namespace std;
+
+/**
+ * Http client implementation.
+ *
+ * @author Mark Slee <mcslee@facebook.com>
+ */
+
+// Yeah, yeah, hacky to put these here, I know.
+static const char* CRLF = "\r\n";
+static const int CRLF_LEN = 2;
+
+ THttpClient::THttpClient(boost::shared_ptr<TTransport> transport, string host, string path) :
+ transport_(transport),
+ host_(host),
+ path_(path),
+ readHeaders_(true),
+ chunked_(false),
+ chunkSize_(0),
+ contentLength_(0),
+ httpBuf_(NULL),
+ httpBufPos_(0),
+ httpBufSize_(1024) {
+ init();
+}
+
+THttpClient::THttpClient(string host, int port, string path) :
+ host_(host),
+ path_(path),
+ readHeaders_(true),
+ chunked_(false),
+ chunkSize_(0),
+ contentLength_(0),
+ httpBuf_(NULL),
+ httpBufPos_(0),
+ httpBufSize_(1024) {
+ transport_ = boost::shared_ptr<TTransport>(new TSocket(host, port));
+ init();
+}
+
+void THttpClient::init() {
+ httpBuf_ = (char*)malloc(httpBufSize_+1);
+ if (httpBuf_ == NULL) {
+ throw TTransportException("Out of memory.");
+ }
+}
+
+THttpClient::~THttpClient() {
+ if (httpBuf_ != NULL) {
+ free(httpBuf_);
+ }
+}
+
+uint32_t THttpClient::read(uint8_t* buf, uint32_t len) {
+ if (readBuffer_.available() == 0) {
+ readBuffer_.resetBuffer();
+ uint32_t got = readMoreData();
+ if (got == 0) {
+ return 0;
+ }
+ }
+ return readBuffer_.read(buf, len);
+}
+
+uint32_t THttpClient::readMoreData() {
+ // Get more data!
+ refill();
+
+ if (readHeaders_) {
+ readHeaders();
+ }
+
+ if (chunked_) {
+ return readChunked();
+ } else {
+ char* read;
+ read = readContent((char*)httpBuf_, contentLength_);
+ shift(read);
+ return contentLength_;
+ }
+}
+
+uint32_t THttpClient::readChunked() {
+ uint32_t length = 0;
+ char* nextLine = (char*)httpBuf_;
+ while (true) {
+ char* line = nextLine;
+ nextLine = readLine(nextLine);
+ uint32_t chunkSize = parseChunkSize(line);
+ if (chunkSize == 0) {
+ break;
+ }
+ // Read data content
+ nextLine = readContent(nextLine, chunkSize);
+ length += chunkSize;
+
+ // Read trailing CRLF after content
+ nextLine = readLine(nextLine);
+ }
+
+ // Read footer lines until a blank one appears
+ while (true) {
+ char* line = nextLine;
+ nextLine = readLine(nextLine);
+ if (strlen(line) == 0) {
+ break;
+ }
+ }
+
+ // Shift down whatever we have left in the buf
+ shift(nextLine);
+
+ return length;
+}
+
+uint32_t THttpClient::parseChunkSize(char* line) {
+ char* semi = strchr(line, ';');
+ if (semi != NULL) {
+ *semi = '\0';
+ }
+ int s;
+ int size;
+ s = sscanf(line, "%x", &size);
+ return (uint32_t)size;
+}
+
+char* THttpClient::readContent(char* pos, uint32_t size) {
+ uint32_t need = size;
+
+ while (need > 0) {
+ uint32_t avail = httpBufPos_ - (pos - httpBuf_);
+ if (avail == 0) {
+ refill();
+ }
+ uint32_t give = avail;
+ if (need < give) {
+ give = need;
+ }
+ readBuffer_.write((uint8_t*)pos, give);
+ pos += give;
+ need -= give;
+ }
+ return pos;
+}
+
+char* THttpClient::readLine(char* pos) {
+ while (true) {
+ char* eol = NULL;
+
+ // Note, the data we read could have ended right on the CRLF pair
+ if (pos != NULL) {
+ eol = strstr(pos, CRLF);
+ }
+
+ // No CRLF yet?
+ if (eol == NULL) {
+ // Shift whatever we have now to front
+ pos = shift(pos);
+ // Refill the buffer
+ refill();
+ } else {
+ // Return pointer to next line
+ *eol = '\0';
+ return eol + CRLF_LEN;
+ }
+ }
+
+}
+
+char* THttpClient::shift(char* pos) {
+ if (pos != NULL && httpBufPos_ > (pos - httpBuf_)) {
+ // Shift down remaining data and read more
+ uint32_t length = httpBufPos_ - (pos - httpBuf_);
+ memmove(httpBuf_, pos, length);
+ httpBufPos_ = length;
+ } else {
+ httpBufPos_ = 0;
+ }
+ httpBuf_[httpBufPos_] = '\0';
+ return httpBuf_;
+}
+
+void THttpClient::refill() {
+ uint32_t avail = httpBufSize_ - httpBufPos_;
+ if (avail <= (httpBufSize_ / 4)) {
+ httpBufSize_ *= 2;
+ httpBuf_ = (char*)realloc(httpBuf_, httpBufSize_);
+ if (httpBuf_ == NULL) {
+ throw TTransportException("Out of memory.");
+ }
+ }
+
+ // Read more data
+ uint32_t got = transport_->read((uint8_t*)(httpBuf_+httpBufPos_), httpBufSize_-httpBufPos_);
+ httpBufPos_ += got;
+ httpBuf_[httpBufPos_] = '\0';
+
+ if (got == 0) {
+ throw TTransportException("Could not finish reading HTTP headers");
+ }
+}
+
+void THttpClient::readHeaders() {
+ // Initialize headers state variables
+ contentLength_ = 0;
+ chunked_ = false;
+ chunkSize_ = 0;
+
+ // Control state flow
+ bool statusLine = true;
+ bool finished = false;
+
+ // Initialize local pos vars
+ char* nextLine = (char*)httpBuf_;
+
+ // Loop until headers are finished
+ while (true) {
+ char* line = nextLine;
+ nextLine = readLine(nextLine);
+
+ if (strlen(line) == 0) {
+ if (finished) {
+ readHeaders_ = false;
+ shift(nextLine);
+ return;
+ } else {
+ // Must have been an HTTP 100, keep going for another status line
+ statusLine = true;
+ }
+ } else {
+ if (statusLine) {
+ statusLine = false;
+ finished = parseStatusLine(line);
+ } else {
+ parseHeader(line);
+ }
+ }
+ }
+}
+
+bool THttpClient::parseStatusLine(char* status) {
+ char* http = status;
+
+ char* code = strchr(http, ' ');
+ *code = '\0';
+
+ while (*(code++) == ' ');
+
+ char* msg = strchr(code, ' ');
+ *msg = '\0';
+
+ if (strcmp(code, "200") == 0) {
+ // HTTP 200 = OK, we got the response
+ return true;
+ } else if (strcmp(code, "100") == 0) {
+ // HTTP 100 = continue, just keep reading
+ return false;
+ } else {
+ throw TTransportException(status);
+ }
+}
+
+void THttpClient::parseHeader(char* header) {
+ char* colon = strchr(header, ':');
+ if (colon == NULL) {
+ return;
+ }
+ uint32_t sz = colon - header;
+ char* value = colon+1;
+
+ if (strncmp(header, "Transfer-Encoding", sz) == 0) {
+ if (strstr(value, "chunked") != NULL) {
+ chunked_ = true;
+ }
+ } else if (strncmp(header, "Content-Length", sz) == 0) {
+ chunked_ = false;
+ contentLength_ = atoi(value);
+ }
+}
+
+void THttpClient::write(const uint8_t* buf, uint32_t len) {
+ writeBuffer_.write(buf, len);
+}
+
+void THttpClient::flush() {
+ // Fetch the contents of the write buffer
+ uint8_t* buf;
+ uint32_t len;
+ writeBuffer_.getBuffer(&buf, &len);
+
+ // Construct the HTTP header
+ std::ostringstream h;
+ h <<
+ "POST " << path_ << " HTTP/1.1" << CRLF <<
+ "Host: " << host_ << CRLF <<
+ "Content-Type: application/x-thrift" << CRLF <<
+ "Content-Length: " << len << CRLF <<
+ "Accept: application/x-thrift" << CRLF <<
+ "User-Agent: C++/THttpClient" << CRLF <<
+ CRLF;
+ string header = h.str();
+
+ // Write the header, then the data, then flush
+ transport_->write((const uint8_t*)header.c_str(), header.size());
+ transport_->write(buf, len);
+ transport_->flush();
+
+ // Reset the buffer and header variables
+ writeBuffer_.resetBuffer();
+ readHeaders_ = true;
+}
+
+}}} // facebook::thrift::transport