1 files changed, 156 insertions, 0 deletions
diff --git a/ext/json/fbuffer/fbuffer.h b/ext/json/fbuffer/fbuffer.h
new file mode 100644
index 0000000000..7d1dad7404
--- /dev/null
+++ b/ext/json/fbuffer/fbuffer.h
@@ -0,0 +1,156 @@
+
+#ifndef _FBUFFER_H_
+#define _FBUFFER_H_
+
+#include <assert.h>
+#include "ruby.h"
+
+#ifdef HAVE_RUBY_ENCODING_H
+#include "ruby/encoding.h"
+#define FORCE_UTF8(obj) rb_enc_associate((obj), rb_utf8_encoding())
+#else
+#define FORCE_UTF8(obj)
+#endif
+
+/* We don't need to guard objects for rbx, so let's do nothing at all. */
+#ifndef RB_GC_GUARD
+#define RB_GC_GUARD(object)
+#endif
+
+typedef struct FBufferStruct {
+    unsigned long initial_length;
+    char *ptr;
+    unsigned long len;
+    unsigned long capa;
+} FBuffer;
+
+#define FBUFFER_INITIAL_LENGTH_DEFAULT 1024
+
+#define FBUFFER_PTR(fb) (fb->ptr)
+#define FBUFFER_LEN(fb) (fb->len)
+#define FBUFFER_CAPA(fb) (fb->capa)
+#define FBUFFER_PAIR(fb) FBUFFER_PTR(fb), FBUFFER_LEN(fb)
+
+static FBuffer *fbuffer_alloc(unsigned long initial_length);
+static void fbuffer_free(FBuffer *fb);
+static void fbuffer_clear(FBuffer *fb);
+static void fbuffer_append(FBuffer *fb, const char *newstr, unsigned long len);
+static void fbuffer_append_long(FBuffer *fb, long number);
+static void fbuffer_append_char(FBuffer *fb, char newchr);
+static FBuffer *fbuffer_dup(FBuffer *fb);
+static VALUE fbuffer_to_s(FBuffer *fb);
+
+static FBuffer *fbuffer_alloc(unsigned long initial_length)
+{
+    FBuffer *fb;
+    if (initial_length <= 0) initial_length = FBUFFER_INITIAL_LENGTH_DEFAULT;
+    fb = ALLOC(FBuffer);
+    memset((void *) fb, 0, sizeof(FBuffer));
+    fb->initial_length = initial_length;
+    return fb;
+}
+
+static void fbuffer_free(FBuffer *fb)
+{
+    if (fb->ptr) ruby_xfree(fb->ptr);
+    ruby_xfree(fb);
+}
+
+static void fbuffer_clear(FBuffer *fb)
+{
+    fb->len = 0;
+}
+
+static void fbuffer_inc_capa(FBuffer *fb, unsigned long requested)
+{
+    unsigned long required;
+
+    if (!fb->ptr) {
+        fb->ptr = ALLOC_N(char, fb->initial_length);
+        fb->capa = fb->initial_length;
+    }
+
+    for (required = fb->capa; requested > required - fb->len; required <<= 1);
+
+    if (required > fb->capa) {
+        REALLOC_N(fb->ptr, char, required);
+        fb->capa = required;
+    }
+}
+
+static void fbuffer_append(FBuffer *fb, const char *newstr, unsigned long len)
+{
+    if (len > 0) {
+        fbuffer_inc_capa(fb, len);
+        MEMCPY(fb->ptr + fb->len, newstr, char, len);
+        fb->len += len;
+    }
+}
+
+static void fbuffer_append_str(FBuffer *fb, VALUE str)
+{
+    const char *newstr = StringValuePtr(str);
+    unsigned long len = RSTRING_LEN(str);
+
+    RB_GC_GUARD(str);
+
+    fbuffer_append(fb, newstr, len);
+}
+
+static void fbuffer_append_char(FBuffer *fb, char newchr)
+{
+    fbuffer_inc_capa(fb, 1);
+    *(fb->ptr + fb->len) = newchr;
+    fb->len++;
+}
+
+static void freverse(char *start, char *end)
+{
+    char c;
+
+    while (end > start) {
+        c = *end, *end-- = *start, *start++ = c;
+    }
+}
+
+static long fltoa(long number, char *buf)
+{
+    static char digits[] = "0123456789";
+    long sign = number;
+    char* tmp = buf;
+
+    if (sign < 0) number = -number;
+    do *tmp++ = digits[number % 10]; while (number /= 10);
+    if (sign < 0) *tmp++ = '-';
+    freverse(buf, tmp - 1);
+    return tmp - buf;
+}
+
+static void fbuffer_append_long(FBuffer *fb, long number)
+{
+    char buf[20];
+    unsigned long len = fltoa(number, buf);
+    fbuffer_append(fb, buf, len);
+}
+
+static FBuffer *fbuffer_dup(FBuffer *fb)
+{
+    unsigned long len = fb->len;
+    FBuffer *result;
+
+    assert(len > 0);
+    if (len > 0) {
+        result = fbuffer_alloc(len);
+        fbuffer_append(result, FBUFFER_PAIR(fb));
+    }
+    return result;
+}
+
+static VALUE fbuffer_to_s(FBuffer *fb)
+{
+    VALUE result = rb_str_new(FBUFFER_PAIR(fb));
+    fbuffer_free(fb);
+    FORCE_UTF8(result);
+    return result;
+}
+#endif