Restructure files and libraries

Rename a bunch of files to make the consistent
	Create two new subdirectories for common code, and utilities

common/common-governors.c

@@ -0,0 +1,149 @@
+/*
+
+Copyright (c) 2017-2019, Feral Interactive
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+
+ * Redistributions of source code must retain the above copyright notice,
+   this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+   notice, this list of conditions and the following disclaimer in the
+   documentation and/or other materials provided with the distribution.
+ * Neither the name of Feral Interactive nor the names of its contributors
+   may be used to endorse or promote products derived from this software
+   without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
+LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+POSSIBILITY OF SUCH DAMAGE.
+
+ */
+
+#define _GNU_SOURCE
+
+#include "common-governors.h"
+#include "common-logging.h"
+
+#include <assert.h>
+#include <glob.h>
+#include <stdio.h>
+#include <string.h>
+
+/**
+ * Discover all governers on the system.
+ *
+ * Located at /sys/devices/system/cpu/cpu(*)/cpufreq/scaling_governor
+ */
+int fetch_governors(char governors[MAX_GOVERNORS][MAX_GOVERNOR_LENGTH])
+{
+	glob_t glo = { 0 };
+	static const char *path = "/sys/devices/system/cpu/cpu*/cpufreq/scaling_governor";
+
+	/* Assert some sanity on this glob */
+	if (glob(path, GLOB_NOSORT, NULL, &glo) != 0) {
+		LOG_ERROR("glob failed for cpu governors: (%s)\n", strerror(errno));
+		return 0;
+	}
+
+	if (glo.gl_pathc < 1) {
+		globfree(&glo);
+		LOG_ERROR("no cpu governors found\n");
+		return 0;
+	}
+
+	int num_governors = 0;
+
+	/* Walk the glob set */
+	for (size_t i = 0; i < glo.gl_pathc; i++) {
+		if (i >= MAX_GOVERNORS) {
+			break;
+		}
+
+		/* Get the real path to the file.
+		 * Traditionally cpufreq symlinks to a policy directory that can
+		 * be shared, so let's prevent duplicates.
+		 */
+		char fullpath[PATH_MAX] = { 0 };
+		const char *ptr = realpath(glo.gl_pathv[i], fullpath);
+		if (fullpath != ptr) {
+			continue;
+		}
+
+		/* Only add this governor if it is unique */
+		for (int j = 0; j < num_governors; j++) {
+			if (strncmp(fullpath, governors[i], PATH_MAX) == 0) {
+				continue;
+			}
+		}
+
+		/* Copy this governor into the output set */
+		static_assert(MAX_GOVERNOR_LENGTH > PATH_MAX, "possible string truncation");
+		strncpy(governors[num_governors], fullpath, MAX_GOVERNOR_LENGTH);
+		num_governors++;
+	}
+
+	globfree(&glo);
+	return num_governors;
+}
+
+/**
+ * Return the current governor state
+ */
+const char *get_gov_state(void)
+{
+	/* Persistent governor state */
+	static char governor[64] = { 0 };
+	memset(governor, 0, sizeof(governor));
+
+	/* State for all governors */
+	char governors[MAX_GOVERNORS][MAX_GOVERNOR_LENGTH] = { { 0 } };
+	int num = fetch_governors(governors);
+
+	/* Check the list */
+	for (int i = 0; i < num; i++) {
+		const char *gov = governors[i];
+
+		FILE *f = fopen(gov, "r");
+		if (!f) {
+			LOG_ERROR("Failed to open file for read %s\n", gov);
+			continue;
+		}
+
+		/* Grab the file length */
+		fseek(f, 0, SEEK_END);
+		long length = ftell(f);
+		fseek(f, 0, SEEK_SET);
+
+		char contents[length];
+
+		if (fread(contents, 1, (size_t)length, f) > 0) {
+			/* Files have a newline */
+			strtok(contents, "\n");
+			if (strlen(governor) > 0 && strncmp(governor, contents, 64) != 0) {
+				/* Don't handle the mixed case, this shouldn't ever happen
+				 * But it is a clear sign we shouldn't carry on */
+				LOG_ERROR("Governors malformed: got \"%s\", expected \"%s\"", contents, governor);
+				fclose(f);
+				return "malformed";
+			}
+
+			strncpy(governor, contents, sizeof(governor) - 1);
+		} else {
+			LOG_ERROR("Failed to read contents of %s\n", gov);
+		}
+
+		fclose(f);
+	}
+
+	return governor;
+}