Merging upstream version 1.39.0.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 876 insertions, 50 deletions

diff --git a/libnetdata/buffer/buffer.h b/libnetdata/buffer/buffer.h
index 0fa3495b4..f5f83bc2a 100644
--- a/libnetdata/buffer/buffer.h
+++ b/libnetdata/buffer/buffer.h
@@ -3,48 +3,80 @@
 #ifndef NETDATA_WEB_BUFFER_H
 #define NETDATA_WEB_BUFFER_H 1
 
+#include "../string/utf8.h"
 #include "../libnetdata.h"
 
 #define WEB_DATA_LENGTH_INCREASE_STEP 1024
 
+#define BUFFER_JSON_MAX_DEPTH 32 // max is 255
+
+extern const char hex_digits[16];
+extern const char base64_digits[64];
+extern unsigned char hex_value_from_ascii[256];
+extern unsigned char base64_value_from_ascii[256];
+
+typedef enum __attribute__ ((__packed__)) {
+    BUFFER_JSON_EMPTY = 0,
+    BUFFER_JSON_OBJECT,
+    BUFFER_JSON_ARRAY,
+} BUFFER_JSON_NODE_TYPE;
+
+typedef struct web_buffer_json_node {
+    BUFFER_JSON_NODE_TYPE type;
+    uint32_t count:24;
+} BUFFER_JSON_NODE;
+
+#define BUFFER_QUOTE_MAX_SIZE 7
+
+typedef enum __attribute__ ((__packed__)) {
+    WB_CONTENT_CACHEABLE = (1 << 0),
+    WB_CONTENT_NO_CACHEABLE = (1 << 1),
+} BUFFER_OPTIONS;
+
+typedef enum __attribute__ ((__packed__)) {
+    CT_NONE = 0,
+    CT_APPLICATION_JSON,
+    CT_TEXT_PLAIN,
+    CT_TEXT_HTML,
+    CT_APPLICATION_X_JAVASCRIPT,
+    CT_TEXT_CSS,
+    CT_TEXT_XML,
+    CT_APPLICATION_XML,
+    CT_TEXT_XSL,
+    CT_APPLICATION_OCTET_STREAM,
+    CT_APPLICATION_X_FONT_TRUETYPE,
+    CT_APPLICATION_X_FONT_OPENTYPE,
+    CT_APPLICATION_FONT_WOFF,
+    CT_APPLICATION_FONT_WOFF2,
+    CT_APPLICATION_VND_MS_FONTOBJ,
+    CT_IMAGE_SVG_XML,
+    CT_IMAGE_PNG,
+    CT_IMAGE_JPG,
+    CT_IMAGE_GIF,
+    CT_IMAGE_XICON,
+    CT_IMAGE_ICNS,
+    CT_IMAGE_BMP,
+    CT_PROMETHEUS,
+} HTTP_CONTENT_TYPE;
+
 typedef struct web_buffer {
-    size_t size;        	// allocation size of buffer, in bytes
-    size_t len;     		// current data length in buffer, in bytes
-    char *buffer;   		// the buffer itself
-    uint8_t contenttype;	// the content type of the data in the buffer
-    uint8_t options;		// options related to the content
-    time_t date;    		// the timestamp this content has been generated
-    time_t expires;			// the timestamp this content expires
+    size_t size;            // allocation size of buffer, in bytes
+    size_t len;             // current data length in buffer, in bytes
+    char *buffer;           // the buffer itself
+    HTTP_CONTENT_TYPE content_type;    // the content type of the data in the buffer
+    BUFFER_OPTIONS options; // options related to the content
+    time_t date;            // the timestamp this content has been generated
+    time_t expires;         // the timestamp this content expires
     size_t *statistics;
-} BUFFER;
 
-// options
-#define WB_CONTENT_CACHEABLE            1
-#define WB_CONTENT_NO_CACHEABLE         2
-
-// content-types
-#define CT_APPLICATION_JSON             1
-#define CT_TEXT_PLAIN                   2
-#define CT_TEXT_HTML                    3
-#define CT_APPLICATION_X_JAVASCRIPT     4
-#define CT_TEXT_CSS                     5
-#define CT_TEXT_XML                     6
-#define CT_APPLICATION_XML              7
-#define CT_TEXT_XSL                     8
-#define CT_APPLICATION_OCTET_STREAM     9
-#define CT_APPLICATION_X_FONT_TRUETYPE  10
-#define CT_APPLICATION_X_FONT_OPENTYPE  11
-#define CT_APPLICATION_FONT_WOFF        12
-#define CT_APPLICATION_FONT_WOFF2       13
-#define CT_APPLICATION_VND_MS_FONTOBJ   14
-#define CT_IMAGE_SVG_XML                15
-#define CT_IMAGE_PNG                    16
-#define CT_IMAGE_JPG                    17
-#define CT_IMAGE_GIF                    18
-#define CT_IMAGE_XICON                  19
-#define CT_IMAGE_ICNS                   20
-#define CT_IMAGE_BMP                    21
-#define CT_PROMETHEUS                   22
+    struct {
+        char key_quote[BUFFER_QUOTE_MAX_SIZE + 1];
+        char value_quote[BUFFER_QUOTE_MAX_SIZE + 1];
+        int8_t depth;
+        bool minify;
+        BUFFER_JSON_NODE stack[BUFFER_JSON_MAX_DEPTH];
+    } json;
+} BUFFER;
 
 #define buffer_cacheable(wb)    do { (wb)->options |= WB_CONTENT_CACHEABLE;    if((wb)->options & WB_CONTENT_NO_CACHEABLE) (wb)->options &= ~WB_CONTENT_NO_CACHEABLE; } while(0)
 #define buffer_no_cacheable(wb) do { (wb)->options |= WB_CONTENT_NO_CACHEABLE; if((wb)->options & WB_CONTENT_CACHEABLE)    (wb)->options &= ~WB_CONTENT_CACHEABLE;  (wb)->expires = 0; } while(0)
@@ -52,12 +84,34 @@ typedef struct web_buffer {
 #define buffer_strlen(wb) ((wb)->len)
 const char *buffer_tostring(BUFFER *wb);
 
-#define buffer_flush(wb) wb->buffer[(wb)->len = 0] = '\0'
-void buffer_reset(BUFFER *wb);
+#define BUFFER_OVERFLOW_EOF "EOF"
+
+#ifdef NETDATA_INTERNAL_CHECKS
+#define buffer_overflow_check(b) _buffer_overflow_check(b)
+#else
+#define buffer_overflow_check(b)
+#endif
+
+static inline void _buffer_overflow_check(BUFFER *b) {
+    assert(b->len <= b->size &&
+                   "BUFFER: length is above buffer size.");
+
+    assert(!(b->buffer && (b->buffer[b->size] != '\0' || strcmp(&b->buffer[b->size + 1], BUFFER_OVERFLOW_EOF) != 0)) &&
+                   "BUFFER: detected overflow.");
+}
+
+static inline void buffer_flush(BUFFER *wb) {
+    wb->len = 0;
 
-void buffer_strcat(BUFFER *wb, const char *txt);
-void buffer_fast_strcat(BUFFER *wb, const char *txt, size_t len);
-void buffer_rrd_value(BUFFER *wb, NETDATA_DOUBLE value);
+    wb->json.depth = 0;
+    wb->json.stack[0].type = BUFFER_JSON_EMPTY;
+    wb->json.stack[0].count = 0;
+
+    if(wb->buffer)
+        wb->buffer[0] = '\0';
+}
+
+void buffer_reset(BUFFER *wb);
 
 void buffer_date(BUFFER *wb, int year, int month, int day, int hours, int minutes, int seconds);
 void buffer_jsdate(BUFFER *wb, int year, int month, int day, int hours, int minutes, int seconds);
@@ -69,22 +123,794 @@ void buffer_increase(BUFFER *b, size_t free_size_required);
 void buffer_snprintf(BUFFER *wb, size_t len, const char *fmt, ...) PRINTFLIKE(3, 4);
 void buffer_vsprintf(BUFFER *wb, const char *fmt, va_list args);
 void buffer_sprintf(BUFFER *wb, const char *fmt, ...) PRINTFLIKE(2,3);
-void buffer_strcat_jsonescape(BUFFER *wb, const char *txt);
 void buffer_strcat_htmlescape(BUFFER *wb, const char *txt);
 
 void buffer_char_replace(BUFFER *wb, char from, char to);
 
-char *print_number_lu_r(char *str, unsigned long uvalue);
-char *print_number_llu_r(char *str, unsigned long long uvalue);
-char *print_number_llu_r_smart(char *str, unsigned long long uvalue);
-
-void buffer_print_llu(BUFFER *wb, unsigned long long uvalue);
-void buffer_print_ll(BUFFER *wb, long long value);
-void buffer_print_llu_hex(BUFFER *wb, unsigned long long value);
+void buffer_print_sn_flags(BUFFER *wb, SN_FLAGS flags, bool send_anomaly_bit);
 
 static inline void buffer_need_bytes(BUFFER *buffer, size_t needed_free_size) {
-    if(unlikely(buffer->size - buffer->len < needed_free_size))
-        buffer_increase(buffer, needed_free_size);
+    if(unlikely(buffer->len + needed_free_size >= buffer->size))
+        buffer_increase(buffer, needed_free_size + 1);
+}
+
+void buffer_json_initialize(BUFFER *wb, const char *key_quote, const char *value_quote, int depth,
+                            bool add_anonymous_object, bool minify);
+
+void buffer_json_finalize(BUFFER *wb);
+
+static inline void _buffer_json_depth_push(BUFFER *wb, BUFFER_JSON_NODE_TYPE type) {
+#ifdef NETDATA_INTERNAL_CHECKS
+    assert(wb->json.depth <= BUFFER_JSON_MAX_DEPTH && "BUFFER JSON: max nesting reached");
+#endif
+    wb->json.depth++;
+    wb->json.stack[wb->json.depth].count = 0;
+    wb->json.stack[wb->json.depth].type = type;
+}
+
+static inline void _buffer_json_depth_pop(BUFFER *wb) {
+    wb->json.depth--;
+}
+
+static inline void buffer_fast_charcat(BUFFER *wb, const char c) {
+
+    buffer_need_bytes(wb, 2);
+    *(&wb->buffer[wb->len]) = c;
+    wb->len += 1;
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_fast_rawcat(BUFFER *wb, const char *txt, size_t len) {
+    if(unlikely(!txt || !*txt || !len)) return;
+
+    buffer_need_bytes(wb, len + 1);
+
+    const char *t = txt;
+    const char *e = &txt[len];
+
+    char *d = &wb->buffer[wb->len];
+
+    while(t != e)
+        *d++ = *t++;
+
+    wb->len += len;
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_fast_strcat(BUFFER *wb, const char *txt, size_t len) {
+    if(unlikely(!txt || !*txt || !len)) return;
+
+    buffer_need_bytes(wb, len + 1);
+
+    const char *t = txt;
+    const char *e = &txt[len];
+
+    char *d = &wb->buffer[wb->len];
+
+    while(t != e
+#ifdef NETDATA_INTERNAL_CHECKS
+          && *t
+#endif
+            )
+        *d++ = *t++;
+
+#ifdef NETDATA_INTERNAL_CHECKS
+    assert(!(t != e && !*t) && "BUFFER: source string is shorter than the length given.");
+#endif
+
+    wb->len += len;
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_strcat(BUFFER *wb, const char *txt) {
+    if(unlikely(!txt || !*txt)) return;
+
+    const char *t = txt;
+    while(*t) {
+        buffer_need_bytes(wb, 100);
+        char *s = &wb->buffer[wb->len];
+        char *d = s;
+        const char *e = &wb->buffer[wb->size];
+
+        while(*t && d < e)
+            *d++ = *t++;
+
+        wb->len += d - s;
+    }
+
+    buffer_need_bytes(wb, 1);
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_strncat(BUFFER *wb, const char *txt, size_t len) {
+    if(unlikely(!txt || !*txt)) return;
+
+    const char *t = txt;
+    while(*t) {
+        buffer_need_bytes(wb, len);
+        char *s = &wb->buffer[wb->len];
+        char *d = s;
+        const char *e = &wb->buffer[wb->len + len];
+
+        while(*t && d < e)
+            *d++ = *t++;
+
+        wb->len += d - s;
+    }
+
+    buffer_need_bytes(wb, 1);
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_json_strcat(BUFFER *wb, const char *txt) {
+    if(unlikely(!txt || !*txt)) return;
+
+    const unsigned char *t = (const unsigned char *)txt;
+    while(*t) {
+        buffer_need_bytes(wb, 110);
+        unsigned char *s = (unsigned char *)&wb->buffer[wb->len];
+        unsigned char *d = s;
+        const unsigned char *e = (unsigned char *)&wb->buffer[wb->size - 10]; // make room for the max escape sequence
+
+        while(*t && d < e) {
+#ifdef BUFFER_JSON_ESCAPE_UTF
+            if(unlikely(IS_UTF8_STARTBYTE(*t) && IS_UTF8_BYTE(t[1]))) {
+                // UTF-8 multi-byte encoded character
+
+                // find how big this character is (2-4 bytes)
+                size_t utf_character_size = 2;
+                while(utf_character_size < 4 && t[utf_character_size] && IS_UTF8_BYTE(t[utf_character_size]) && !IS_UTF8_STARTBYTE(t[utf_character_size]))
+                    utf_character_size++;
+
+                uint32_t code_point = 0;
+                for (size_t i = 0; i < utf_character_size; i++) {
+                    code_point <<= 6;
+                    code_point |= (t[i] & 0x3F);
+                }
+
+                t += utf_character_size;
+
+                // encode as \u escape sequence
+                *d++ = '\\';
+                *d++ = 'u';
+                *d++ = hex_digits[(code_point >> 12) & 0xf];
+                *d++ = hex_digits[(code_point >> 8) & 0xf];
+                *d++ = hex_digits[(code_point >> 4) & 0xf];
+                *d++ = hex_digits[code_point & 0xf];
+            }
+            else
+#endif
+            if(unlikely(*t < ' ')) {
+                uint32_t v = *t++;
+                *d++ = '\\';
+                *d++ = 'u';
+                *d++ = hex_digits[(v >> 12) & 0xf];
+                *d++ = hex_digits[(v >> 8) & 0xf];
+                *d++ = hex_digits[(v >> 4) & 0xf];
+                *d++ = hex_digits[v & 0xf];
+            }
+            else {
+                if (unlikely(*t == '\\' || *t == '\"'))
+                    *d++ = '\\';
+
+                *d++ = *t++;
+            }
+        }
+
+        wb->len += d - s;
+    }
+
+    buffer_need_bytes(wb, 1);
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_json_quoted_strcat(BUFFER *wb, const char *txt) {
+    if(unlikely(!txt || !*txt)) return;
+
+    if(*txt == '"')
+        txt++;
+
+    const char *t = txt;
+    while(*t) {
+        buffer_need_bytes(wb, 100);
+        char *s = &wb->buffer[wb->len];
+        char *d = s;
+        const char *e = &wb->buffer[wb->size - 1]; // remove 1 to make room for the escape character
+
+        while(*t && d < e) {
+            if(unlikely(*t == '"' && !t[1])) {
+                t++;
+                continue;
+            }
+
+            if(unlikely(*t == '\\' || *t == '"'))
+                *d++ = '\\';
+
+            *d++ = *t++;
+        }
+
+        wb->len += d - s;
+    }
+
+    buffer_need_bytes(wb, 1);
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+// This trick seems to give an 80% speed increase in 32bit systems
+// print_number_llu_r() will just print the digits up to the
+// point the remaining value fits in 32 bits, and then calls
+// print_number_lu_r() to print the rest with 32 bit arithmetic.
+
+static inline char *print_uint32_reversed(char *dst, uint32_t value) {
+    char *d = dst;
+    do *d++ = (char)('0' + (value % 10)); while((value /= 10));
+    return d;
+}
+
+static inline char *print_uint64_reversed(char *dst, uint64_t value) {
+#ifdef ENV32BIT
+    if(value <= (uint64_t)0xffffffff)
+        return print_uint32_reversed(dst, value);
+
+    char *d = dst;
+    do *d++ = (char)('0' + (value % 10)); while((value /= 10) && value > (uint64_t)0xffffffff);
+    if(value) return print_uint32_reversed(d, value);
+    return d;
+#else
+    char *d = dst;
+    do *d++ = (char)('0' + (value % 10)); while((value /= 10));
+    return d;
+#endif
+}
+
+static inline char *print_uint32_hex_reversed(char *dst, uint32_t value) {
+    static const char *digits = "0123456789ABCDEF";
+    char *d = dst;
+    do *d++ = digits[value & 0xf]; while((value >>= 4));
+    return d;
+}
+
+static inline char *print_uint64_hex_reversed(char *dst, uint64_t value) {
+#ifdef ENV32BIT
+    if(value <= (uint64_t)0xffffffff)
+        return print_uint32_hex_reversed(dst, value);
+
+    char *d = dst;
+    do *d++ = hex_digits[value & 0xf]; while((value >>= 4) && value > (uint64_t)0xffffffff);
+    if(value) return print_uint32_hex_reversed(d, value);
+    return d;
+#else
+    char *d = dst;
+    do *d++ = hex_digits[value & 0xf]; while((value >>= 4));
+    return d;
+#endif
+}
+
+static inline char *print_uint64_base64_reversed(char *dst, uint64_t value) {
+    char *d = dst;
+    do *d++ = base64_digits[value & 63]; while ((value >>= 6));
+    return d;
+}
+
+static inline void char_array_reverse(char *from, char *to) {
+    // from and to are inclusive
+    char *begin = from, *end = to, aux;
+    while (end > begin) aux = *end, *end-- = *begin, *begin++ = aux;
+}
+
+static inline int print_netdata_double(char *dst, NETDATA_DOUBLE value) {
+    char *s = dst;
+
+    if(unlikely(value < 0)) {
+        *s++ = '-';
+        value = fabsndd(value);
+    }
+
+    uint64_t fractional_precision = 10000000ULL; // fractional part 7 digits
+    int fractional_wanted_digits = 7;
+    int exponent = 0;
+    if(unlikely(value >= (NETDATA_DOUBLE)(UINT64_MAX / 10))) {
+        // the number is too big to print using 64bit numbers
+        // so, let's convert it to exponential notation
+        exponent = (int)(floorndd(log10ndd(value)));
+        value /= powndd(10, exponent);
+
+        // the max precision we can support is 18 digits
+        // (UINT64_MAX is 20, but the first is 1)
+        fractional_precision = 1000000000000000000ULL; // fractional part 18 digits
+        fractional_wanted_digits = 18;
+    }
+
+    char *d = s;
+    NETDATA_DOUBLE integral_d, fractional_d;
+    fractional_d = modfndd(value, &integral_d);
+
+    // get the integral and the fractional parts as 64-bit integers
+    uint64_t integral = (uint64_t)integral_d;
+    uint64_t fractional = (uint64_t)llrintndd(fractional_d * (NETDATA_DOUBLE)fractional_precision);
+    if(unlikely(fractional >= fractional_precision)) {
+        integral++;
+        fractional -= fractional_precision;
+    }
+
+    // convert the integral part to string (reversed)
+    d = print_uint64_reversed(d, integral);
+    char_array_reverse(s, d - 1);      // copy reversed the integral string
+
+    if(likely(fractional != 0)) {
+        *d++ = '.'; // add the dot
+
+        // convert the fractional part to string (reversed)
+        d = print_uint64_reversed(s = d, fractional);
+
+        while(d - s < fractional_wanted_digits) *d++ = '0'; // prepend zeros to reach precision
+        char_array_reverse(s, d - 1);   // copy reversed the fractional string
+
+        // remove trailing zeros from the fractional part
+        while(*(d - 1) == '0') d--;
+    }
+
+    if(unlikely(exponent != 0)) {
+        *d++ = 'e';
+        *d++ = '+';
+        d = print_uint32_reversed(s = d, exponent);
+        char_array_reverse(s, d - 1);
+    }
+
+    *d = '\0';
+    return (int)(d - dst);
+}
+
+static inline void buffer_print_uint64(BUFFER *wb, uint64_t value) {
+    buffer_need_bytes(wb, 50);
+
+    char *s = &wb->buffer[wb->len];
+    char *d = print_uint64_reversed(s, value);
+    char_array_reverse(s, d - 1);
+    *d = '\0';
+    wb->len += d - s;
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_int64(BUFFER *wb, int64_t value) {
+    buffer_need_bytes(wb, 50);
+
+    if(value < 0) {
+        buffer_fast_strcat(wb, "-", 1);
+        value = -value;
+    }
+
+    buffer_print_uint64(wb, (uint64_t)value);
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_uint64_hex(BUFFER *wb, uint64_t value) {
+    buffer_need_bytes(wb, sizeof(uint64_t) * 2 + 2 + 1);
+
+    buffer_fast_strcat(wb, HEX_PREFIX, sizeof(HEX_PREFIX) - 1);
+
+    char *s = &wb->buffer[wb->len];
+    char *d = print_uint64_hex_reversed(s, value);
+    char_array_reverse(s, d - 1);
+    *d = '\0';
+    wb->len += d - s;
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_uint64_base64(BUFFER *wb, uint64_t value) {
+    buffer_need_bytes(wb, sizeof(uint64_t) * 2 + 2 + 1);
+
+    buffer_fast_strcat(wb, IEEE754_UINT64_B64_PREFIX, sizeof(IEEE754_UINT64_B64_PREFIX) - 1);
+
+    char *s = &wb->buffer[wb->len];
+    char *d = print_uint64_base64_reversed(s, value);
+    char_array_reverse(s, d - 1);
+    *d = '\0';
+    wb->len += d - s;
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_int64_hex(BUFFER *wb, int64_t value) {
+    buffer_need_bytes(wb, 2);
+
+    if(value < 0) {
+        buffer_fast_strcat(wb, "-", 1);
+        value = -value;
+    }
+
+    buffer_print_uint64_hex(wb, (uint64_t)value);
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_int64_base64(BUFFER *wb, int64_t value) {
+    buffer_need_bytes(wb, 2);
+
+    if(value < 0) {
+        buffer_fast_strcat(wb, "-", 1);
+        value = -value;
+    }
+
+    buffer_print_uint64_base64(wb, (uint64_t)value);
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_netdata_double(BUFFER *wb, NETDATA_DOUBLE value) {
+    buffer_need_bytes(wb, 512 + 2);
+
+    if(isnan(value) || isinf(value)) {
+        buffer_fast_strcat(wb, "null", 4);
+        return;
+    }
+    else
+        wb->len += print_netdata_double(&wb->buffer[wb->len], value);
+
+    // terminate it
+    buffer_need_bytes(wb, 1);
+    wb->buffer[wb->len] = '\0';
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_netdata_double_hex(BUFFER *wb, NETDATA_DOUBLE value) {
+    buffer_need_bytes(wb, sizeof(uint64_t) * 2 + 2 + 1 + 1);
+
+    uint64_t *ptr = (uint64_t *) (&value);
+    buffer_fast_strcat(wb, IEEE754_DOUBLE_HEX_PREFIX, sizeof(IEEE754_DOUBLE_HEX_PREFIX) - 1);
+
+    char *s = &wb->buffer[wb->len];
+    char *d = print_uint64_hex_reversed(s, *ptr);
+    char_array_reverse(s, d - 1);
+    *d = '\0';
+    wb->len += d - s;
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_netdata_double_base64(BUFFER *wb, NETDATA_DOUBLE value) {
+    buffer_need_bytes(wb, sizeof(uint64_t) * 2 + 2 + 1 + 1);
+
+    uint64_t *ptr = (uint64_t *) (&value);
+    buffer_fast_strcat(wb, IEEE754_DOUBLE_B64_PREFIX, sizeof(IEEE754_DOUBLE_B64_PREFIX) - 1);
+
+    char *s = &wb->buffer[wb->len];
+    char *d = print_uint64_base64_reversed(s, *ptr);
+    char_array_reverse(s, d - 1);
+    *d = '\0';
+    wb->len += d - s;
+
+    buffer_overflow_check(wb);
+}
+
+typedef enum {
+    NUMBER_ENCODING_DECIMAL,
+    NUMBER_ENCODING_HEX,
+    NUMBER_ENCODING_BASE64,
+} NUMBER_ENCODING;
+
+static inline void buffer_print_int64_encoded(BUFFER *wb, NUMBER_ENCODING encoding, int64_t value) {
+    if(encoding == NUMBER_ENCODING_BASE64)
+        return buffer_print_int64_base64(wb, value);
+
+    if(encoding == NUMBER_ENCODING_HEX)
+        return buffer_print_int64_hex(wb, value);
+
+    return buffer_print_int64(wb, value);
+}
+
+static inline void buffer_print_uint64_encoded(BUFFER *wb, NUMBER_ENCODING encoding, uint64_t value) {
+    if(encoding == NUMBER_ENCODING_BASE64)
+        return buffer_print_uint64_base64(wb, value);
+
+    if(encoding == NUMBER_ENCODING_HEX)
+        return buffer_print_uint64_hex(wb, value);
+
+    return buffer_print_uint64(wb, value);
+}
+
+static inline void buffer_print_netdata_double_encoded(BUFFER *wb, NUMBER_ENCODING encoding, NETDATA_DOUBLE value) {
+    if(encoding == NUMBER_ENCODING_BASE64)
+        return buffer_print_netdata_double_base64(wb, value);
+
+    if(encoding == NUMBER_ENCODING_HEX)
+        return buffer_print_netdata_double_hex(wb, value);
+
+    return buffer_print_netdata_double(wb, value);
+}
+
+static inline void buffer_print_spaces(BUFFER *wb, size_t spaces) {
+    buffer_need_bytes(wb, spaces * 4 + 1);
+
+    char *d = &wb->buffer[wb->len];
+    for(size_t i = 0; i < spaces; i++) {
+        *d++ = ' ';
+        *d++ = ' ';
+        *d++ = ' ';
+        *d++ = ' ';
+    }
+
+    *d = '\0';
+    wb->len += spaces * 4;
+
+    buffer_overflow_check(wb);
+}
+
+static inline void buffer_print_json_comma_newline_spacing(BUFFER *wb) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    if(wb->json.minify)
+        return;
+
+    buffer_fast_strcat(wb, "\n", 1);
+    buffer_print_spaces(wb, wb->json.depth + 1);
+}
+
+static inline void buffer_print_json_key(BUFFER *wb, const char *key) {
+    buffer_strcat(wb, wb->json.key_quote);
+    buffer_json_strcat(wb, key);
+    buffer_strcat(wb, wb->json.key_quote);
+}
+
+static inline void buffer_json_add_string_value(BUFFER *wb, const char *value) {
+    if(value) {
+        buffer_strcat(wb, wb->json.value_quote);
+        buffer_json_strcat(wb, value);
+        buffer_strcat(wb, wb->json.value_quote);
+    }
+    else
+        buffer_fast_strcat(wb, "null", 4);
+}
+
+static inline void buffer_json_add_quoted_string_value(BUFFER *wb, const char *value) {
+    if(value) {
+        buffer_strcat(wb, wb->json.value_quote);
+        buffer_json_quoted_strcat(wb, value);
+        buffer_strcat(wb, wb->json.value_quote);
+    }
+    else
+        buffer_fast_strcat(wb, "null", 4);
+}
+
+static inline void buffer_json_member_add_object(BUFFER *wb, const char *key) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":{", 2);
+    wb->json.stack[wb->json.depth].count++;
+
+    _buffer_json_depth_push(wb, BUFFER_JSON_OBJECT);
+}
+
+static inline void buffer_json_object_close(BUFFER *wb) {
+#ifdef NETDATA_INTERNAL_CHECKS
+    assert(wb->json.depth >= 0 && "BUFFER JSON: nothing is open to close it");
+    assert(wb->json.stack[wb->json.depth].type == BUFFER_JSON_OBJECT && "BUFFER JSON: an object is not open to close it");
+#endif
+    if(!wb->json.minify) {
+        buffer_fast_strcat(wb, "\n", 1);
+        buffer_print_spaces(wb, wb->json.depth);
+    }
+    buffer_fast_strcat(wb, "}", 1);
+    _buffer_json_depth_pop(wb);
+}
+
+static inline void buffer_json_member_add_string(BUFFER *wb, const char *key, const char *value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_json_add_string_value(wb, value);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_string_or_omit(BUFFER *wb, const char *key, const char *value) {
+    if(value && *value)
+        buffer_json_member_add_string(wb, key, value);
+}
+
+static inline void buffer_json_member_add_string_or_empty(BUFFER *wb, const char *key, const char *value) {
+    if(!value)
+        value = "";
+
+    buffer_json_member_add_string(wb, key, value);
+}
+
+static inline void buffer_json_member_add_quoted_string(BUFFER *wb, const char *key, const char *value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+
+    if(!value || strcmp(value, "null") == 0)
+        buffer_fast_strcat(wb, "null", 4);
+    else
+        buffer_json_add_quoted_string_value(wb, value);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_uuid(BUFFER *wb, const char *key, uuid_t *value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+
+    if(value) {
+        char uuid[GUID_LEN + 1];
+        uuid_unparse_lower(*value, uuid);
+        buffer_json_add_string_value(wb, uuid);
+    }
+    else
+        buffer_json_add_string_value(wb, NULL);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_boolean(BUFFER *wb, const char *key, bool value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_strcat(wb, value?"true":"false");
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_array(BUFFER *wb, const char *key) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":[", 2);
+    wb->json.stack[wb->json.depth].count++;
+
+    _buffer_json_depth_push(wb, BUFFER_JSON_ARRAY);
+}
+
+static inline void buffer_json_add_array_item_array(BUFFER *wb) {
+    buffer_print_json_comma_newline_spacing(wb);
+
+    buffer_fast_strcat(wb, "[", 1);
+    wb->json.stack[wb->json.depth].count++;
+
+    _buffer_json_depth_push(wb, BUFFER_JSON_ARRAY);
+}
+
+static inline void buffer_json_add_array_item_string(BUFFER *wb, const char *value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_json_add_string_value(wb, value);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_double(BUFFER *wb, NETDATA_DOUBLE value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_print_netdata_double(wb, value);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_int64(BUFFER *wb, int64_t value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_print_int64(wb, value);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_uint64(BUFFER *wb, uint64_t value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_print_uint64(wb, value);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_time_t(BUFFER *wb, time_t value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_print_int64(wb, value);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_time_ms(BUFFER *wb, time_t value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_print_int64(wb, value);
+    buffer_fast_strcat(wb, "000", 3);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_time_t2ms(BUFFER *wb, time_t value) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_print_int64(wb, value);
+    buffer_fast_strcat(wb, "000", 3);
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_add_array_item_object(BUFFER *wb) {
+    if(wb->json.stack[wb->json.depth].count)
+        buffer_fast_strcat(wb, ",", 1);
+
+    buffer_fast_strcat(wb, "{", 1);
+    wb->json.stack[wb->json.depth].count++;
+
+    _buffer_json_depth_push(wb, BUFFER_JSON_OBJECT);
+}
+
+static inline void buffer_json_member_add_time_t(BUFFER *wb, const char *key, time_t value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_print_int64(wb, value);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_time_t2ms(BUFFER *wb, const char *key, time_t value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_print_int64(wb, value);
+    buffer_fast_strcat(wb, "000", 3);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_uint64(BUFFER *wb, const char *key, uint64_t value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_print_uint64(wb, value);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_int64(BUFFER *wb, const char *key, int64_t value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_print_int64(wb, value);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_member_add_double(BUFFER *wb, const char *key, NETDATA_DOUBLE value) {
+    buffer_print_json_comma_newline_spacing(wb);
+    buffer_print_json_key(wb, key);
+    buffer_fast_strcat(wb, ":", 1);
+    buffer_print_netdata_double(wb, value);
+
+    wb->json.stack[wb->json.depth].count++;
+}
+
+static inline void buffer_json_array_close(BUFFER *wb) {
+#ifdef NETDATA_INTERNAL_CHECKS
+    assert(wb->json.depth >= 0 && "BUFFER JSON: nothing is open to close it");
+    assert(wb->json.stack[wb->json.depth].type == BUFFER_JSON_ARRAY && "BUFFER JSON: an array is not open to close it");
+#endif
+    buffer_fast_strcat(wb, "]", 1);
+    _buffer_json_depth_pop(wb);
 }
 
 #endif /* NETDATA_WEB_BUFFER_H */