X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=stream.cpp;h=2b9a69593a478605800fd21c9585063eebec8d0c;hp=322391ef5c2158dfc04c440301a11b9cc4e792fb;hb=e666e2735bf831084d744027b844de9f4d3fe34d;hpb=195dc469133d0daed6ac69cdef373dc8dade9637

diff --git a/stream.cpp b/stream.cpp
index 322391e..2b9a695 100644
--- a/stream.cpp
+++ b/stream.cpp
@@ -1,13 +1,14 @@
+#include <errno.h>
 #include <stdio.h>
+#include <stdlib.h>
 #include <unistd.h>
-#include <errno.h>
-#include <algorithm>
 #include <string>
 #include <vector>
 
+#include "state.pb.h"
+#include "log.h"
 #include "stream.h"
 #include "util.h"
-#include "state.pb.h"
 
 using namespace std;
 
@@ -31,7 +32,7 @@ Stream::~Stream()
 			ret = close(data_fd);
 		} while (ret == -1 && errno == EINTR);
 		if (ret == -1) {
-			perror("close");
+			log_perror("close");
 		}
 	}
 }
@@ -62,12 +63,88 @@ StreamProto Stream::serialize()
 	data_fd = -1;
 	return serialized;
 }
+	
+void Stream::set_backlog_size(size_t new_size)
+{
+	if (backlog_size == new_size) {
+		return;
+	}
+
+	string existing_data;
+	if (!read_tempfile(data_fd, &existing_data)) {  // Closes data_fd.
+		exit(1);
+	}
+
+	// Unwrap the data so it's no longer circular.
+	if (bytes_received <= backlog_size) {
+		existing_data.resize(bytes_received);
+	} else {
+		size_t pos = bytes_received % backlog_size;
+		existing_data = existing_data.substr(pos, string::npos) +
+			existing_data.substr(0, pos);
+	}
+
+	// See if we need to discard data.
+	if (new_size < existing_data.size()) {
+		size_t to_discard = existing_data.size() - new_size;
+		existing_data = existing_data.substr(to_discard, string::npos);
+	}
+
+	// Create a new, empty data file.
+	data_fd = make_tempfile("");
+	backlog_size = new_size;
+
+	// Now cheat a bit by rewinding, and adding all the old data back.
+	bytes_received -= existing_data.size();
+	add_data(existing_data.data(), existing_data.size());
+}
 
 void Stream::put_client_to_sleep(Client *client)
 {
 	sleeping_clients.push_back(client);
 }
 
+void Stream::add_data(const char *data, ssize_t bytes)
+{
+	size_t pos = bytes_received % backlog_size;
+	bytes_received += bytes;
+
+	if (pos + bytes > backlog_size) {
+		ssize_t to_copy = backlog_size - pos;
+		while (to_copy > 0) {
+			int ret = pwrite(data_fd, data, to_copy, pos);
+			if (ret == -1 && errno == EINTR) {
+				continue;
+			}
+			if (ret == -1) {
+				log_perror("pwrite");
+				// Dazed and confused, but trying to continue...
+				break;
+			}
+			pos += ret;
+			data += ret;
+			to_copy -= ret;
+			bytes -= ret;
+		}
+		pos = 0;
+	}
+
+	while (bytes > 0) {
+		int ret = pwrite(data_fd, data, bytes, pos);
+		if (ret == -1 && errno == EINTR) {
+			continue;
+		}
+		if (ret == -1) {
+			log_perror("pwrite");
+			// Dazed and confused, but trying to continue...
+			break;
+		}
+		pos += ret;
+		data += ret;
+		bytes -= ret;
+	}
+}
+
 void Stream::wake_up_all_clients()
 {
 	if (to_process.empty()) {