dep: Add cpuinfo

dep/cpuinfo/src/linux/smallfile.c

@@ -0,0 +1,70 @@
+#include <stdbool.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <alloca.h>
+#include <errno.h>
+
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <unistd.h>
+#include <fcntl.h>
+
+#if CPUINFO_MOCK
+	#include <cpuinfo-mock.h>
+#endif
+#include <linux/api.h>
+#include <cpuinfo/log.h>
+
+
+bool cpuinfo_linux_parse_small_file(const char* filename, size_t buffer_size, cpuinfo_smallfile_callback callback, void* context) {
+	int file = -1;
+	bool status = false;
+	char* buffer = (char*) alloca(buffer_size);
+
+	#if CPUINFO_LOG_DEBUG_PARSERS
+		cpuinfo_log_debug("parsing small file %s", filename);
+	#endif
+
+#if CPUINFO_MOCK
+	file = cpuinfo_mock_open(filename, O_RDONLY);
+#else
+	file = open(filename, O_RDONLY);
+#endif
+	if (file == -1) {
+		cpuinfo_log_info("failed to open %s: %s", filename, strerror(errno));
+		goto cleanup;
+	}
+
+	size_t buffer_position = 0;
+	ssize_t bytes_read;
+	do {
+#if CPUINFO_MOCK
+		bytes_read = cpuinfo_mock_read(file, &buffer[buffer_position], buffer_size - buffer_position);
+#else
+		bytes_read = read(file, &buffer[buffer_position], buffer_size - buffer_position);
+#endif
+		if (bytes_read < 0) {
+			cpuinfo_log_info("failed to read file %s at position %zu: %s", filename, buffer_position, strerror(errno));
+			goto cleanup;
+		}
+		buffer_position += (size_t) bytes_read;
+		if (buffer_position >= buffer_size) {
+			cpuinfo_log_error("failed to read file %s: insufficient buffer of size %zu", filename, buffer_size);
+			goto cleanup;
+		}
+	} while (bytes_read != 0);
+
+	status = callback(buffer, &buffer[buffer_position], context);
+
+cleanup:
+	if (file != -1) {
+#if CPUINFO_MOCK
+		cpuinfo_mock_close(file);
+#else
+		close(file);
+#endif
+		file = -1;
+	}
+	return status;
+}