Merge pull request #4333 from opensourcerouting/printfrr

printfrr() world domination tour

1 files changed, 249 insertions, 0 deletions

diff --git a/lib/printf/glue.c b/lib/printf/glue.c
new file mode 100644
index 0000000000..1b760dc2d3
--- /dev/null
+++ b/lib/printf/glue.c
@@ -0,0 +1,249 @@
+/*
+ * Copyright (c) 2019  David Lamparter, for NetDEF, Inc.
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+
+#include <sys/types.h>
+#include <string.h>
+#include <wchar.h>
+
+#include "printfrr.h"
+#include "printflocal.h"
+
+ssize_t bprintfrr(struct fbuf *out, const char *fmt, ...)
+{
+	ssize_t ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vbprintfrr(out, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+ssize_t vsnprintfrr(char *out, size_t outsz, const char *fmt, va_list ap)
+{
+	struct fbuf fbb = { .buf = out, .pos = out, .len = outsz - 1, };
+	struct fbuf *fb = (out && outsz) ? &fbb : NULL;
+	ssize_t ret;
+
+	ret = vbprintfrr(fb, fmt, ap);
+	if (fb)
+		fb->pos[0] = '\0';
+	return ret;
+}
+
+ssize_t snprintfrr(char *out, size_t outsz, const char *fmt, ...)
+{
+	struct fbuf fbb = { .buf = out, .pos = out, .len = outsz - 1, };
+	struct fbuf *fb = (out && outsz) ? &fbb : NULL;
+	ssize_t ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vbprintfrr(fb, fmt, ap);
+	va_end(ap);
+	if (fb)
+		fb->pos[0] = '\0';
+	return ret;
+}
+
+ssize_t vcsnprintfrr(char *out, size_t outsz, const char *fmt, va_list ap)
+{
+	if (!out || !outsz)
+		return vbprintfrr(NULL, fmt, ap);
+
+	struct fbuf fbb = { .buf = out, .pos = out, .len = outsz - 1, };
+	ssize_t ret;
+	size_t pos;
+
+	pos = strnlen(out, outsz);
+	fbb.pos += pos;
+
+	ret = vbprintfrr(&fbb, fmt, ap);
+	fbb.pos[0] = '\0';
+	return ret >= 0 ? ret + (ssize_t)pos : ret;
+}
+
+ssize_t csnprintfrr(char *out, size_t outsz, const char *fmt, ...)
+{
+	ssize_t ret;
+	va_list ap;
+
+	va_start(ap, fmt);
+	ret = vcsnprintfrr(out, outsz, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+char *vasnprintfrr(struct memtype *mt, char *out, size_t outsz, const char *fmt,
+		   va_list ap)
+{
+	struct fbuf fb = { .buf = out, .pos = out, .len = outsz - 1, };
+	ssize_t len;
+	va_list ap2;
+	char *ret = out;
+
+	va_copy(ap2, ap);
+	len = vbprintfrr(&fb, fmt, ap);
+	if (len < 0)
+		/* error = malformed format string => try something useful */
+		return qstrdup(mt, fmt);
+
+	if ((size_t)len >= outsz - 1) {
+		ret = qmalloc(mt, len + 1);
+		fb.buf = fb.pos = ret;
+		fb.len = len;
+
+		vbprintfrr(&fb, fmt, ap2);
+	}
+	ret[len] = '\0';
+	return ret;
+}
+
+char *asnprintfrr(struct memtype *mt, char *out, size_t outsz, const char *fmt,
+		  ...)
+{
+	va_list ap;
+	char *ret;
+
+	va_start(ap, fmt);
+	ret = vasnprintfrr(mt, out, outsz, fmt, ap);
+	va_end(ap);
+	return ret;
+}
+
+char *vasprintfrr(struct memtype *mt, const char *fmt, va_list ap)
+{
+	char buf[256];
+	char *ret;
+
+	ret = vasnprintfrr(mt, buf, sizeof(buf), fmt, ap);
+
+	if (ret == buf)
+		ret = qstrdup(mt, ret);
+	return ret;
+}
+
+char *asprintfrr(struct memtype *mt, const char *fmt, ...)
+{
+	char buf[256];
+	va_list ap;
+	char *ret;
+
+	va_start(ap, fmt);
+	ret = vasnprintfrr(mt, buf, sizeof(buf), fmt, ap);
+	va_end(ap);
+
+	if (ret == buf)
+		ret = qstrdup(mt, ret);
+	return ret;
+}
+
+/* Q: WTF?
+ * A: since printf should be reasonably fast (think debugging logs), the idea
+ *    here is to keep things close by each other in a cacheline.  That's why
+ *    ext_quick just has the first 2 characters of an extension, and we do a
+ *    nice linear continuous sweep.  Only if we find something, we go do more
+ *    expensive things.
+ *
+ * Q: doesn't this need a mutex/lock?
+ * A: theoretically, yes, but that's quite expensive and I rather elide that
+ *    necessity by putting down some usage rules.  Just call this at startup
+ *    while singlethreaded and all is fine.  Ideally, just use constructors
+ *    (and make sure dlopen() doesn't mess things up...)
+ */
+#define MAXEXT 64
+
+struct ext_quick {
+	char fmt[2];
+};
+
+static uint8_t ext_offsets[26] __attribute__((aligned(32)));
+static struct ext_quick entries[MAXEXT] __attribute__((aligned(64)));
+static const struct printfrr_ext *exts[MAXEXT] __attribute__((aligned(64)));
+
+void printfrr_ext_reg(const struct printfrr_ext *ext)
+{
+	uint8_t o;
+	ptrdiff_t i;
+
+	if (!printfrr_ext_char(ext->match[0]))
+		return;
+
+	o = ext->match[0] - 'A';
+	for (i = ext_offsets[o];
+			i < MAXEXT && entries[i].fmt[0] &&
+			memcmp(entries[i].fmt, ext->match, 2) < 0;
+			i++)
+		;
+	if (i == MAXEXT)
+		return;
+	for (o++; o <= 'Z' - 'A'; o++)
+		ext_offsets[o]++;
+
+	memmove(entries + i + 1, entries + i,
+			(MAXEXT - i - 1) * sizeof(entries[0]));
+	memmove(exts + i + 1, exts + i,
+			(MAXEXT - i - 1) * sizeof(exts[0]));
+
+	memcpy(entries[i].fmt, ext->match, 2);
+	exts[i] = ext;
+}
+
+ssize_t printfrr_extp(char *buf, size_t sz, const char *fmt, int prec,
+		      const void *ptr)
+{
+	const struct printfrr_ext *ext;
+	size_t i;
+
+	for (i = ext_offsets[fmt[0] - 'A']; i < MAXEXT; i++) {
+		if (!entries[i].fmt[0] || entries[i].fmt[0] > fmt[0])
+			return 0;
+		if (entries[i].fmt[1] && entries[i].fmt[1] != fmt[1])
+			continue;
+		ext = exts[i];
+		if (!ext->print_ptr)
+			continue;
+		if (strncmp(ext->match, fmt, strlen(ext->match)))
+			continue;
+		return ext->print_ptr(buf, sz, fmt, prec, ptr);
+	}
+	return 0;
+}
+
+ssize_t printfrr_exti(char *buf, size_t sz, const char *fmt, int prec,
+		      uintmax_t num)
+{
+	const struct printfrr_ext *ext;
+	size_t i;
+
+	for (i = ext_offsets[fmt[0] - 'A']; i < MAXEXT; i++) {
+		if (!entries[i].fmt[0] || entries[i].fmt[0] > fmt[0])
+			return 0;
+		if (entries[i].fmt[1] && entries[i].fmt[1] != fmt[1])
+			continue;
+		ext = exts[i];
+		if (!ext->print_int)
+			continue;
+		if (strncmp(ext->match, fmt, strlen(ext->match)))
+			continue;
+		return ext->print_int(buf, sz, fmt, prec, num);
+	}
+	return 0;
+}