dep: Add cpuinfo

dep/cpuinfo/src/linux/multiline.c

@@ -0,0 +1,106 @@
+#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_multiline_file(const char* filename, size_t buffer_size, cpuinfo_line_callback callback, void* context)
+{
+	int file = -1;
+	bool status = false;
+	char* buffer = (char*) alloca(buffer_size);
+
+#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;
+	}
+
+	/* Only used for error reporting */
+	size_t position = 0;
+	uint64_t line_number = 1;
+	const char* buffer_end = &buffer[buffer_size];
+	char* data_start = buffer;
+	ssize_t bytes_read;
+	do {
+#if CPUINFO_MOCK
+		bytes_read = cpuinfo_mock_read(file, data_start, (size_t) (buffer_end - data_start));
+#else
+		bytes_read = read(file, data_start, (size_t) (buffer_end - data_start));
+#endif
+		if (bytes_read < 0) {
+			cpuinfo_log_info("failed to read file %s at position %zu: %s",
+				filename, position, strerror(errno));
+			goto cleanup;
+		}
+
+		position += (size_t) bytes_read;
+		const char* data_end = data_start + (size_t) bytes_read;
+		const char* line_start = buffer;
+
+		if (bytes_read == 0) {
+			/* No more data in the file: process the remaining text in the buffer as a single entry */
+			const char* line_end = data_end;
+			if (!callback(line_start, line_end, context, line_number)) {
+				goto cleanup;
+			}
+		} else {
+			const char* line_end;
+			do {
+				/* Find the end of the entry, as indicated by newline character ('\n') */
+				for (line_end = line_start; line_end != data_end; line_end++) {
+					if (*line_end == '\n') {
+						break;
+					}
+				}
+
+				/*
+				 * If we located separator at the end of the entry, parse it.
+				 * Otherwise, there may be more data at the end; read the file once again.
+				 */
+				if (line_end != data_end) {
+					if (!callback(line_start, line_end, context, line_number++)) {
+						goto cleanup;
+					}
+					line_start = line_end + 1;
+				}
+			} while (line_end != data_end);
+
+			/* Move remaining partial line data at the end to the beginning of the buffer */
+			const size_t line_length = (size_t) (line_end - line_start);
+			memmove(buffer, line_start, line_length);
+			data_start = &buffer[line_length];
+		}
+	} while (bytes_read != 0);
+
+	/* Commit */
+	status = true;
+
+cleanup:
+	if (file != -1) {
+#if CPUINFO_MOCK
+		cpuinfo_mock_close(file);
+#else
+		close(file);
+#endif
+		file = -1;
+	}
+	return status;
+}