1 files changed, 286 insertions, 0 deletions
diff --git a/src/xz/util.c b/src/xz/util.c
new file mode 100644
index 0000000..9f9a8fb
--- /dev/null
+++ b/src/xz/util.c
@@ -0,0 +1,286 @@
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file       util.c
+/// \brief      Miscellaneous utility functions
+//
+//  Author:     Lasse Collin
+//
+//  This file has been put into the public domain.
+//  You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "private.h"
+#include <stdarg.h>
+
+
+/// Buffers for uint64_to_str() and uint64_to_nicestr()
+static char bufs[4][128];
+
+/// Thousand separator support in uint64_to_str() and uint64_to_nicestr()
+static enum { UNKNOWN, WORKS, BROKEN } thousand = UNKNOWN;
+
+
+extern void *
+xrealloc(void *ptr, size_t size)
+{
+	assert(size > 0);
+
+	// Save ptr so that we can free it if realloc fails.
+	// The point is that message_fatal ends up calling stdio functions
+	// which in some libc implementations might allocate memory from
+	// the heap. Freeing ptr improves the chances that there's free
+	// memory for stdio functions if they need it.
+	void *p = ptr;
+	ptr = realloc(ptr, size);
+
+	if (ptr == NULL) {
+		const int saved_errno = errno;
+		free(p);
+		message_fatal("%s", strerror(saved_errno));
+	}
+
+	return ptr;
+}
+
+
+extern char *
+xstrdup(const char *src)
+{
+	assert(src != NULL);
+	const size_t size = strlen(src) + 1;
+	char *dest = xmalloc(size);
+	return memcpy(dest, src, size);
+}
+
+
+extern uint64_t
+str_to_uint64(const char *name, const char *value, uint64_t min, uint64_t max)
+{
+	uint64_t result = 0;
+
+	// Skip blanks.
+	while (*value == ' ' || *value == '\t')
+		++value;
+
+	// Accept special value "max". Supporting "min" doesn't seem useful.
+	if (strcmp(value, "max") == 0)
+		return max;
+
+	if (*value < '0' || *value > '9')
+		message_fatal(_("%s: Value is not a non-negative "
+				"decimal integer"), value);
+
+	do {
+		// Don't overflow.
+		if (result > UINT64_MAX / 10)
+			goto error;
+
+		result *= 10;
+
+		// Another overflow check
+		const uint32_t add = (uint32_t)(*value - '0');
+		if (UINT64_MAX - add < result)
+			goto error;
+
+		result += add;
+		++value;
+	} while (*value >= '0' && *value <= '9');
+
+	if (*value != '\0') {
+		// Look for suffix. Originally this supported both base-2
+		// and base-10, but since there seems to be little need
+		// for base-10 in this program, treat everything as base-2
+		// and also be more relaxed about the case of the first
+		// letter of the suffix.
+		uint64_t multiplier = 0;
+		if (*value == 'k' || *value == 'K')
+			multiplier = UINT64_C(1) << 10;
+		else if (*value == 'm' || *value == 'M')
+			multiplier = UINT64_C(1) << 20;
+		else if (*value == 'g' || *value == 'G')
+			multiplier = UINT64_C(1) << 30;
+
+		++value;
+
+		// Allow also e.g. Ki, KiB, and KB.
+		if (*value != '\0' && strcmp(value, "i") != 0
+				&& strcmp(value, "iB") != 0
+				&& strcmp(value, "B") != 0)
+			multiplier = 0;
+
+		if (multiplier == 0) {
+			message(V_ERROR, _("%s: Invalid multiplier suffix"),
+					value - 1);
+			message_fatal(_("Valid suffixes are `KiB' (2^10), "
+					"`MiB' (2^20), and `GiB' (2^30)."));
+		}
+
+		// Don't overflow here either.
+		if (result > UINT64_MAX / multiplier)
+			goto error;
+
+		result *= multiplier;
+	}
+
+	if (result < min || result > max)
+		goto error;
+
+	return result;
+
+error:
+	message_fatal(_("Value of the option `%s' must be in the range "
+				"[%" PRIu64 ", %" PRIu64 "]"),
+				name, min, max);
+}
+
+
+extern uint64_t
+round_up_to_mib(uint64_t n)
+{
+	return (n >> 20) + ((n & ((UINT32_C(1) << 20) - 1)) != 0);
+}
+
+
+/// Check if thousands separator is supported. Run-time checking is easiest
+/// because it seems to be sometimes lacking even on a POSIXish system.
+/// Note that trying to use thousands separators when snprintf() doesn't
+/// support them results in undefined behavior. This just has happened to
+/// work well enough in practice.
+///
+/// DJGPP 2.05 added support for thousands separators but it's broken
+/// at least under WinXP with Finnish locale that uses a non-breaking space
+/// as the thousands separator. Workaround by disabling thousands separators
+/// for DJGPP builds.
+static void
+check_thousand_sep(uint32_t slot)
+{
+	if (thousand == UNKNOWN) {
+		bufs[slot][0] = '\0';
+#ifndef __DJGPP__
+		snprintf(bufs[slot], sizeof(bufs[slot]), "%'u", 1U);
+#endif
+		thousand = bufs[slot][0] == '1' ? WORKS : BROKEN;
+	}
+
+	return;
+}
+
+
+extern const char *
+uint64_to_str(uint64_t value, uint32_t slot)
+{
+	assert(slot < ARRAY_SIZE(bufs));
+
+	check_thousand_sep(slot);
+
+	if (thousand == WORKS)
+		snprintf(bufs[slot], sizeof(bufs[slot]), "%'" PRIu64, value);
+	else
+		snprintf(bufs[slot], sizeof(bufs[slot]), "%" PRIu64, value);
+
+	return bufs[slot];
+}
+
+
+extern const char *
+uint64_to_nicestr(uint64_t value, enum nicestr_unit unit_min,
+		enum nicestr_unit unit_max, bool always_also_bytes,
+		uint32_t slot)
+{
+	assert(unit_min <= unit_max);
+	assert(unit_max <= NICESTR_TIB);
+	assert(slot < ARRAY_SIZE(bufs));
+
+	check_thousand_sep(slot);
+
+	enum nicestr_unit unit = NICESTR_B;
+	char *pos = bufs[slot];
+	size_t left = sizeof(bufs[slot]);
+
+	if ((unit_min == NICESTR_B && value < 10000)
+			|| unit_max == NICESTR_B) {
+		// The value is shown as bytes.
+		if (thousand == WORKS)
+			my_snprintf(&pos, &left, "%'u", (unsigned int)value);
+		else
+			my_snprintf(&pos, &left, "%u", (unsigned int)value);
+	} else {
+		// Scale the value to a nicer unit. Unless unit_min and
+		// unit_max limit us, we will show at most five significant
+		// digits with one decimal place.
+		double d = (double)(value);
+		do {
+			d /= 1024.0;
+			++unit;
+		} while (unit < unit_min || (d > 9999.9 && unit < unit_max));
+
+		if (thousand == WORKS)
+			my_snprintf(&pos, &left, "%'.1f", d);
+		else
+			my_snprintf(&pos, &left, "%.1f", d);
+	}
+
+	static const char suffix[5][4] = { "B", "KiB", "MiB", "GiB", "TiB" };
+	my_snprintf(&pos, &left, " %s", suffix[unit]);
+
+	if (always_also_bytes && value >= 10000) {
+		if (thousand == WORKS)
+			snprintf(pos, left, " (%'" PRIu64 " B)", value);
+		else
+			snprintf(pos, left, " (%" PRIu64 " B)", value);
+	}
+
+	return bufs[slot];
+}
+
+
+extern void
+my_snprintf(char **pos, size_t *left, const char *fmt, ...)
+{
+	va_list ap;
+	va_start(ap, fmt);
+	const int len = vsnprintf(*pos, *left, fmt, ap);
+	va_end(ap);
+
+	// If an error occurred, we want the caller to think that the whole
+	// buffer was used. This way no more data will be written to the
+	// buffer. We don't need better error handling here, although it
+	// is possible that the result looks garbage on the terminal if
+	// e.g. an UTF-8 character gets split. That shouldn't (easily)
+	// happen though, because the buffers used have some extra room.
+	if (len < 0 || (size_t)(len) >= *left) {
+		*left = 0;
+	} else {
+		*pos += len;
+		*left -= (size_t)(len);
+	}
+
+	return;
+}
+
+
+extern bool
+is_tty_stdin(void)
+{
+	const bool ret = isatty(STDIN_FILENO);
+
+	if (ret)
+		message_error(_("Compressed data cannot be read from "
+				"a terminal"));
+
+	return ret;
+}
+
+
+extern bool
+is_tty_stdout(void)
+{
+	const bool ret = isatty(STDOUT_FILENO);
+
+	if (ret)
+		message_error(_("Compressed data cannot be written to "
+				"a terminal"));
+
+	return ret;
+}