Move the “read the whole file” logic into a new file.
authorSteinar H. Gunderson <sgunderson@bigfoot.com>
Sat, 13 Apr 2013 16:47:58 +0000 (18:47 +0200)
committerSteinar H. Gunderson <sgunderson@bigfoot.com>
Sat, 13 Apr 2013 16:47:58 +0000 (18:47 +0200)
Makefile
main.cpp
util.cpp [new file with mode: 0644]
util.h [new file with mode: 0644]

index f99e226..d7209aa 100644 (file)
--- a/Makefile
+++ b/Makefile
@@ -4,7 +4,7 @@ PROTOC=protoc
 CXXFLAGS=-Wall -O2 -g
 LDLIBS=-lpthread -lprotobuf
 
-OBJS=main.o server.o serverpool.o mutexlock.o input.o httpinput.o udpinput.o parse.o config.o markpool.o acceptor.o stats.o thread.o state.pb.o
+OBJS=main.o server.o serverpool.o mutexlock.o input.o httpinput.o udpinput.o parse.o config.o markpool.o acceptor.o stats.o thread.o util.o state.pb.o
 
 all: cubemap
 
index 2771f39..e48bdf1 100644 (file)
--- a/main.cpp
+++ b/main.cpp
@@ -31,6 +31,7 @@
 #include "serverpool.h"
 #include "input.h"
 #include "stats.h"
+#include "util.h"
 #include "version.h"
 #include "state.pb.h"
 
@@ -44,36 +45,6 @@ void hup(int ignored)
        hupped = true;
 }
 
-// Serialize the given state to a file descriptor, and return the (still open)
-// descriptor.
-int make_tempfile(const CubemapStateProto &state)
-{
-       char tmpl[] = "/tmp/cubemapstate.XXXXXX";
-       int state_fd = mkstemp(tmpl);
-       if (state_fd == -1) {
-               perror("mkstemp");
-               exit(1);
-       }
-
-       string serialized;
-       state.SerializeToString(&serialized);
-
-       const char *ptr = serialized.data();
-       size_t to_write = serialized.size();
-       while (to_write > 0) {
-               ssize_t ret = write(state_fd, ptr, to_write);
-               if (ret == -1) {
-                       perror("write");
-                       exit(1);
-               }
-
-               ptr += ret;
-               to_write -= ret;
-       }
-
-       return state_fd;
-}
-
 CubemapStateProto collect_state(const timeval &serialize_start,
                                 const vector<Acceptor *> acceptors,
                                 const vector<Input *> inputs,
@@ -94,42 +65,6 @@ CubemapStateProto collect_state(const timeval &serialize_start,
        return state;
 }
 
-// Read the state back from the file descriptor made by make_tempfile,
-// and close it.
-CubemapStateProto read_tempfile(int state_fd)
-{
-       if (lseek(state_fd, 0, SEEK_SET) == -1) {
-               perror("lseek");
-               exit(1);
-       }
-
-       string serialized;
-       char buf[4096];
-       for ( ;; ) {
-               ssize_t ret = read(state_fd, buf, sizeof(buf));
-               if (ret == -1) {
-                       perror("read");
-                       exit(1);
-               }
-               if (ret == 0) {
-                       // EOF.
-                       break;
-               }
-
-               serialized.append(string(buf, buf + ret));
-       }
-
-       close(state_fd);  // Implicitly deletes the file.
-
-       CubemapStateProto state;
-       if (!state.ParseFromString(serialized)) {
-               fprintf(stderr, "PANIC: Failed deserialization of state.\n");
-               exit(1);
-       }
-
-       return state;
-}
-       
 // Find all port statements in the configuration file, and create acceptors for htem.
 vector<Acceptor *> create_acceptors(
        const Config &config,
@@ -336,7 +271,14 @@ start:
        map<int, Acceptor *> deserialized_acceptors;
        if (state_fd != -1) {
                fprintf(stderr, "Deserializing state from previous process... ");
-               loaded_state = read_tempfile(state_fd);
+               string serialized;
+               if (!read_tempfile(atoi(argv[3]), &serialized)) {
+                       exit(1);
+               }
+               if (!loaded_state.ParseFromString(serialized)) {
+                       fprintf(stderr, "ERROR: Failed deserialization of state.\n");
+                       exit(1);
+               }
 
                serialize_start.tv_sec = loaded_state.serialize_start_sec();
                serialize_start.tv_usec = loaded_state.serialize_start_usec();
@@ -423,8 +365,14 @@ start:
        servers->stop();
 
        fprintf(stderr, "Serializing state and re-execing...\n");
-       state_fd = make_tempfile(collect_state(
-               serialize_start, acceptors, inputs, servers));
+       CubemapStateProto state = collect_state(
+                serialize_start, acceptors, inputs, servers);
+       string serialized;
+       state.SerializeToString(&serialized);
+       state_fd = make_tempfile(serialized);
+       if (state_fd == -1) {
+               exit(1);
+       }
        delete servers;
 
        if (!dry_run_config(argv[0], config_filename)) {
diff --git a/util.cpp b/util.cpp
new file mode 100644 (file)
index 0000000..c8e26d2
--- /dev/null
+++ b/util.cpp
@@ -0,0 +1,74 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <errno.h>
+
+#include "util.h"
+
+using namespace std;
+
+int make_tempfile(const std::string &contents)
+{
+       char filename[] = "/tmp/cubemap.XXXXXX";
+       int fd = mkstemp(filename);
+       if (fd == -1) {
+               perror("mkstemp");
+               return -1;
+       }
+
+       if (unlink(filename) == -1) {
+               perror("unlink");
+               // Can still continue;
+       }
+
+       const char *ptr = contents.data();
+       size_t to_write = contents.size();
+       while (to_write > 0) {
+               ssize_t ret = write(fd, ptr, to_write);
+               if (ret == -1) {
+                       perror("write");
+                       close(fd);
+                       return -1;
+               }
+
+               ptr += ret;
+               to_write -= ret;
+       }
+
+       return fd;
+}
+
+bool read_tempfile(int fd, std::string *contents)
+{
+       if (lseek(fd, 0, SEEK_SET) == -1) {
+               perror("lseek");
+               return false;
+       }
+
+       char buf[4096];
+       for ( ;; ) {
+               ssize_t ret = read(fd, buf, sizeof(buf));
+               if (ret == -1) {
+                       perror("read");
+                       return false;
+               }
+               if (ret == 0) {
+                       // EOF.
+                       break;
+               }
+
+               contents->append(string(buf, buf + ret));
+       }
+
+       int ret;
+       do {
+               ret = close(fd);  // Implicitly deletes the files.
+       } while (ret == -1 && errno == EINTR);
+       
+       if (ret == -1) {
+               perror("close");
+               // Can still continue.
+       }
+
+       return true;
+}
diff --git a/util.h b/util.h
new file mode 100644 (file)
index 0000000..f64e257
--- /dev/null
+++ b/util.h
@@ -0,0 +1,15 @@
+#ifndef _UTIL_H
+#define _UTIL_H
+
+// Some utilities for reading and writing to temporary files.
+
+#include <string>
+
+// Make a file in /tmp, unlink it, and write <contents> to it.
+// Returns the opened file descriptor, or -1 on failure.
+int make_tempfile(const std::string &contents);
+
+// Opposite of make_tempfile(). Returns false on failure.
+bool read_tempfile(int fd, std::string *contents);
+
+#endif  // !defined(_UTIL_H