X-Git-Url: http://git.marmaro.de/?a=blobdiff_plain;f=sbr%2Fcharstring.c;fp=sbr%2Fcharstring.c;h=ff311f10122c879cb9b3e59e59195e79fb434e27;hb=1546f528c670a4a55d0016a754a8f062674a9efe;hp=0000000000000000000000000000000000000000;hpb=b97368925e31edcfc6f69366d7b725e6a4d9881e;p=mmh

diff --git a/sbr/charstring.c b/sbr/charstring.c
new file mode 100644
index 0000000..ff311f1
--- /dev/null
+++ b/sbr/charstring.c
@@ -0,0 +1,154 @@
+/* charstring.c -- dynamically-sized char array that can report size
+ *			   in both characters and bytes
+ *
+ * This code is Copyright (c) 2014, by the authors of nmh.  See the
+ * COPYRIGHT file in the root directory of the nmh distribution for
+ * complete copyright information.
+ */
+
+#include <h/mh.h>
+#include <h/utils.h>
+
+#define CHARSTRING_DEFAULT_SIZE 64
+
+struct charstring {
+	char *buffer;  /* the char array, not always null-terminated */
+	size_t max;    /* current size of the char array, in bytes */
+	char *cur;     /* size in bytes = cur - buffer, without trailing null */
+};
+
+
+static void
+charstring_reserve(charstring_t s, size_t need)
+{
+	const size_t cur = s->cur - s->buffer;
+
+	while (need >= s->max - cur) {
+		/* Insufficient capacity, so double it. */
+		s->buffer = mh_xrealloc(s->buffer, s->max *= 2);
+		s->cur = s->buffer + cur;
+	}
+}
+
+/*
+ * max is in characters
+ */
+charstring_t
+charstring_create(size_t max)
+{
+	charstring_t s = mh_xcalloc(1, sizeof(*s));
+
+	s->max = max ? max : CHARSTRING_DEFAULT_SIZE;
+	s->cur = s->buffer = mh_xcalloc(s->max, 1);
+
+	return s;
+}
+
+charstring_t
+charstring_copy(const charstring_t src)
+{
+	const size_t num = src->cur - src->buffer;
+	charstring_t s = mh_xcalloc(1, sizeof(*s));
+
+	s->max = src->max;
+	s->buffer = mh_xcalloc(s->max, 1);
+	memcpy(s->buffer, src->buffer, num);
+	s->cur = s->buffer + num;
+
+	return s;
+}
+
+/*
+ * OK to call charstring_free with a NULL argument.
+ */
+void
+charstring_free(charstring_t s)
+{
+	if (s) {
+		free(s->buffer);
+		free(s);
+	}
+}
+
+void
+charstring_push_back(charstring_t s, const char c)
+{
+	charstring_reserve(s, s->cur - s->buffer + 1);
+	*s->cur++ = c;
+}
+
+/*
+ * num is the number of bytes in c
+ */
+void
+charstring_push_back_chars(charstring_t s, const char c[], size_t num)
+{
+	charstring_reserve(s, s->cur - s->buffer + num);
+	memcpy(s->cur, c, num);
+	s->cur += num;
+}
+
+void
+charstring_append(charstring_t dest, const charstring_t src)
+{
+	const size_t num = src->cur - src->buffer;
+
+	if (num > 0) {
+		charstring_reserve(dest, dest->cur - dest->buffer + num);
+		memcpy(dest->cur, src->buffer, num);
+		dest->cur += num;
+	}
+}
+
+void
+charstring_append_cstring(charstring_t dest, const char src[])
+{
+	const size_t num = strlen(src);
+
+	if (num > 0) {
+		charstring_reserve(dest, dest->cur - dest->buffer + num);
+		memcpy(dest->cur, src, num);  /* Exclude src's trailing NUL. */
+		dest->cur += num;
+	}
+}
+
+void
+charstring_clear(charstring_t s)
+{
+	s->cur = s->buffer;
+}
+
+/*
+ * Don't store return value of charstring_buffer() and use later after
+ * intervening push_back's; use charstring_buffer_copy() instead.
+ */
+const char *
+charstring_buffer(const charstring_t s)
+{
+	charstring_reserve(s, s->cur - s->buffer + 1);
+
+	/* This is the only place that we null-terminate the buffer. */
+	*s->cur = '\0';
+	/* Don't increment cur so that more can be appended later, and so
+	   that charstring_bytes() behaves as strlen() by not counting the
+	   null. */
+
+	return s->buffer;
+}
+
+char *
+charstring_buffer_copy(const charstring_t s)
+{
+	char *copy = mh_xcalloc(s->cur - s->buffer + 1, 1);
+
+	/* Use charstring_buffer() to null terminate the buffer. */
+	memcpy(copy, charstring_buffer(s), s->cur - s->buffer + 1);
+
+	return copy;
+}
+
+size_t
+charstring_bytes(const charstring_t s)
+{
+	return s->cur - s->buffer;
+}