[ion/simulator] Add StateFile support

ion/src/simulator/shared/state_file.cpp

@@ -0,0 +1,89 @@
+#include <ion.h>
+#include <ion/events.h>
+#include <stdio.h>
+#include <string.h>
+#include "journal.h"
+
+namespace Ion {
+namespace Simulator {
+namespace StateFile {
+
+static constexpr const char * sHeader = "NWSF";
+static constexpr int sHeaderLength = 4;
+static constexpr int sVersionLength = 8;
+
+/* File format: * "NWSF" + "XXXXXXXX" (version) + EVENTS... */
+
+static inline bool load(FILE * f) {
+  char buffer[sVersionLength+1];
+
+  // Header
+  buffer[sHeaderLength] = 0;
+  if (fread(buffer, sHeaderLength, 1, f) != 1) {
+    return false;
+  }
+  printf("READ\n");
+  if (strcmp(buffer, sHeader) != 0) {
+    return false;
+  }
+
+  // Software version
+  buffer[sVersionLength] = 0;
+  if (fread(buffer, sVersionLength, 1, f) != 1) {
+    return false;
+  }
+  if (strcmp(buffer, softwareVersion()) != 0) {
+    return false;
+  }
+
+  // Events
+  Ion::Events::Journal * journal = Journal::replayJournal();
+  while (fread(buffer, 1, 1, f) == 1) {
+    Ion::Events::Event e = Ion::Events::Event(buffer[0]);
+    journal->pushEvent(e);
+  }
+  Ion::Events::replayFrom(journal);
+
+  return true;
+}
+
+void load(const char * filename) {
+  FILE * f = fopen(filename, "rb");
+  if (f == nullptr) {
+    return;
+  }
+  load(f);
+  fclose(f);
+}
+
+static inline bool save(FILE * f) {
+  if (fwrite(sHeader, sHeaderLength, 1, f) != 1) {
+    return false;
+  }
+  if (fwrite(softwareVersion(), sVersionLength, 1, f) != 1) {
+    return false;
+  }
+  Ion::Events::Journal * journal = Journal::logJournal();
+  Ion::Events::Event e;
+  while (!journal->isEmpty()) {
+    Ion::Events::Event e = journal->popEvent();
+    uint8_t code = static_cast<uint8_t>(e);
+    if (fwrite(&code, 1, 1, f) != 1) {
+      return false;
+    }
+  }
+  return true;
+}
+
+void save(const char * filename) {
+  FILE * f = fopen(filename, "w");
+  if (f == nullptr) {
+    return;
+  }
+  save(f);
+  fclose(f);
+}
+
+}
+}
+}

ion/src/simulator/shared/state_file.h

@@ -0,0 +1,15 @@
+#ifndef ION_SIMULATOR_STATE_FILE_H
+#define ION_SIMULATOR_STATE_FILE_H
+
+namespace Ion {
+namespace Simulator {
+namespace StateFile {
+
+void load(const char * filename);
+void save(const char * filename);
+
+}
+}
+}
+
+#endif