First commit

Signed-off-by: Mattias Andrée <m@maandree.se>

1 files changed, 169 insertions, 0 deletions

diff --git a/common.c b/common.c
new file mode 100644
index 0000000..11d72ac
--- /dev/null
+++ b/common.c
@@ -0,0 +1,169 @@
+/* See LICENSE file for copyright and license details. */
+#include "common.h"
+
+
+void
+writeall(const char *s, size_t n)
+{
+	ssize_t r;
+	while (n) {
+		r = write(STDOUT_FILENO, s, n);
+		if (r < 0) {
+			if (errno == EINTR)
+				continue;
+			fprintf(stderr, "%s: write <stdout>: %s\n", argv0, strerror(errno));
+			exit(1);
+		}
+		s = &s[r];
+		n -= (size_t)r;
+	}
+}
+
+
+void
+writechar(uint_least32_t cp)
+{
+	char buf[4];
+
+	if (cp < UINT32_C(0x80)) {
+		buf[0] = (char)cp;
+		writeall(buf, 1u);
+	} else if (cp < UINT32_C(0x800)) {
+		buf[0] = (char)(( cp >> 6) | 0xC0u);
+		buf[1] = (char)(((cp >> 0) & 0x3Fu) | 0x80u);
+		writeall(buf, 2u);
+	} else if (cp < UINT32_C(0x10000)) {
+		buf[0] = (char)(( cp >> 12) | 0xE0u);
+		buf[1] = (char)(((cp >> 6) & 0x3Fu) | 0x80u);
+		buf[2] = (char)(((cp >> 0) & 0x3Fu) | 0x80u);
+		writeall(buf, 3u);
+	} else if (cp < UINT32_C(0x110000)) {
+		buf[0] = (char)(( cp >> 18) | 0xF0u);
+		buf[1] = (char)(((cp >> 12) & 0x3Fu) | 0x80u);
+		buf[2] = (char)(((cp >>  6) & 0x3Fu) | 0x80u);
+		buf[3] = (char)(((cp >>  0) & 0x3Fu) | 0x80u);
+		writeall(buf, 4u);
+	} else {
+		abort();
+	}
+}
+
+
+int
+convert(enum libcharconv_result (*conv)(const char *, size_t, size_t *, uint_least32_t *, size_t *))
+{
+	char *buf = NULL;
+	size_t bufsize = 0;
+	size_t head = 0;
+	size_t tail = 0;
+	ssize_t r;
+	enum libcharconv_result res;
+	size_t n;
+	uint_least32_t *cps;
+	size_t ncps;
+	size_t cps_size = 16u;
+	size_t i;
+
+	cps = malloc(cps_size * sizeof(*cps));
+	if (!cps) {
+		fprintf(stderr, "%s: out of memory\n", argv0);
+		exit(1);
+	}
+
+	for (;;) {
+		if (head == bufsize) {
+			if (tail) {
+				memmove(&buf[0], &buf[tail], head -= tail);
+				tail = 0;
+			} else {
+				buf = realloc(buf, bufsize += 8 << 10);
+				if (!buf) {
+					fprintf(stderr, "%s: out of memory\n", argv0);
+					exit(1);
+				}
+			}
+		}
+		r = read(STDIN_FILENO, &buf[head], bufsize - head);
+		if (r <= 0) {
+			if (!r)
+				break;
+			if (errno == EINTR)
+				continue;
+			fprintf(stderr, "%s: read <stdin>: %s\n", argv0, strerror(errno));
+			exit(1);
+		}
+		head += (size_t)r;
+	conv_again:
+		ncps = cps_size;
+		res = (*conv)(&buf[tail], head - tail, &n, cps, &ncps);
+		if (ncps > cps_size) {
+			cps_size = ncps;
+			cps = realloc(cps, cps_size * sizeof(*cps));
+			if (!cps) {
+				fprintf(stderr, "%s: out of memory\n", argv0);
+				exit(1);
+			}
+			goto conv_again;
+		}
+		switch (res) {
+		case LIBCHARCONV_NO_CONVERT:
+			writeall(&buf[tail], n);
+			tail += n;
+			if (tail != head)
+				goto conv_again;
+			break;
+		case LIBCHARCONV_CONVERTED:
+			for (i = 0u; i < ncps; i++)
+				writechar(cps[i]);
+			tail += n;
+			if (tail != head)
+				goto conv_again;
+			break;
+		case LIBCHARCONV_INDETERMINATE:
+		case LIBCHARCONV_CONVERT_IF_END:
+			break;
+		default:
+			abort();
+		}
+	}
+
+	while (tail < head) {
+		ncps = cps_size;
+		res = (*conv)(&buf[tail], head - tail, &n, cps, &ncps);
+		if (ncps > cps_size) {
+			cps_size = ncps;
+			cps = realloc(cps, cps_size * sizeof(*cps));
+			if (!cps) {
+				fprintf(stderr, "%s: out of memory\n", argv0);
+				exit(1);
+			}
+			continue;
+		}
+		switch (res) {
+		case LIBCHARCONV_INDETERMINATE:
+			n = head - tail;
+			/* fall through */
+		case LIBCHARCONV_NO_CONVERT:
+			writeall(&buf[tail], n);
+			tail += n;
+			break;
+		case LIBCHARCONV_CONVERTED:
+		case LIBCHARCONV_CONVERT_IF_END:
+			for (i = 0u; i < ncps; i++)
+				writechar(cps[i]);
+			tail += n;
+			break;
+		default:
+			abort();
+		}
+	}
+
+	if (close(STDOUT_FILENO)) {
+		fprintf(stderr, "%s: write <stdout>: %s\n", argv0, strerror(errno));
+		exit(1);
+	}
+
+	free(buf);
+	free(cps);
+	return 0;
+}