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-rw-r--r--libnetdata/buffer/Makefile.am8
-rw-r--r--libnetdata/buffer/README.md16
-rw-r--r--libnetdata/buffer/buffer.c525
-rw-r--r--libnetdata/buffer/buffer.h89
4 files changed, 638 insertions, 0 deletions
diff --git a/libnetdata/buffer/Makefile.am b/libnetdata/buffer/Makefile.am
new file mode 100644
index 0000000..161784b
--- /dev/null
+++ b/libnetdata/buffer/Makefile.am
@@ -0,0 +1,8 @@
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+AUTOMAKE_OPTIONS = subdir-objects
+MAINTAINERCLEANFILES = $(srcdir)/Makefile.in
+
+dist_noinst_DATA = \
+ README.md \
+ $(NULL)
diff --git a/libnetdata/buffer/README.md b/libnetdata/buffer/README.md
new file mode 100644
index 0000000..c5f66e6
--- /dev/null
+++ b/libnetdata/buffer/README.md
@@ -0,0 +1,16 @@
+<!--
+title: "BUFFER"
+custom_edit_url: https://github.com/netdata/netdata/edit/master/libnetdata/buffer/README.md
+-->
+
+# BUFFER
+
+`BUFFER` is a convenience library for working with strings in `C`.
+Mainly, `BUFFER`s eliminate the need for tracking the string length, thus providing
+a safe alternative for string operations.
+
+Also, they are super fast in printing and appending data to the string and its `buffer_strlen()`
+is just a lookup (it does not traverse the string).
+
+Netdata uses `BUFFER`s for preparing web responses and buffering data to be sent upstream or
+to external databases.
diff --git a/libnetdata/buffer/buffer.c b/libnetdata/buffer/buffer.c
new file mode 100644
index 0000000..d094058
--- /dev/null
+++ b/libnetdata/buffer/buffer.c
@@ -0,0 +1,525 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+#define BUFFER_OVERFLOW_EOF "EOF"
+
+static inline void buffer_overflow_init(BUFFER *b)
+{
+ b->buffer[b->size] = '\0';
+ strcpy(&b->buffer[b->size + 1], BUFFER_OVERFLOW_EOF);
+}
+
+#ifdef NETDATA_INTERNAL_CHECKS
+#define buffer_overflow_check(b) _buffer_overflow_check(b, __FILE__, __FUNCTION__, __LINE__)
+#else
+#define buffer_overflow_check(b)
+#endif
+
+static inline void _buffer_overflow_check(BUFFER *b, const char *file, const char *function, const unsigned long line)
+{
+ if(b->len > b->size) {
+ error("BUFFER: length %zu is above size %zu, at line %lu, at function %s() of file '%s'.", b->len, b->size, line, function, file);
+ b->len = b->size;
+ }
+
+ if(b->buffer[b->size] != '\0' || strcmp(&b->buffer[b->size + 1], BUFFER_OVERFLOW_EOF) != 0) {
+ error("BUFFER: detected overflow at line %lu, at function %s() of file '%s'.", line, function, file);
+ buffer_overflow_init(b);
+ }
+}
+
+
+void buffer_reset(BUFFER *wb)
+{
+ buffer_flush(wb);
+
+ wb->contenttype = CT_TEXT_PLAIN;
+ wb->options = 0;
+ wb->date = 0;
+ wb->expires = 0;
+
+ buffer_overflow_check(wb);
+}
+
+const char *buffer_tostring(BUFFER *wb)
+{
+ buffer_need_bytes(wb, 1);
+ wb->buffer[wb->len] = '\0';
+
+ buffer_overflow_check(wb);
+
+ return(wb->buffer);
+}
+
+void buffer_char_replace(BUFFER *wb, char from, char to)
+{
+ char *s = wb->buffer, *end = &wb->buffer[wb->len];
+
+ while(s != end) {
+ if(*s == from) *s = to;
+ s++;
+ }
+
+ 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.
+
+inline char *print_number_lu_r(char *str, unsigned long uvalue) {
+ char *wstr = str;
+
+ // print each digit
+ do *wstr++ = (char)('0' + (uvalue % 10)); while(uvalue /= 10);
+ return wstr;
+}
+
+inline char *print_number_llu_r(char *str, unsigned long long uvalue) {
+ char *wstr = str;
+
+ // print each digit
+ do *wstr++ = (char)('0' + (uvalue % 10)); while((uvalue /= 10) && uvalue > (unsigned long long)0xffffffff);
+ if(uvalue) return print_number_lu_r(wstr, uvalue);
+ return wstr;
+}
+
+inline char *print_number_llu_r_smart(char *str, unsigned long long uvalue) {
+ switch (sizeof(void *)) {
+ case 4:
+ str = (uvalue > (unsigned long long) 0xffffffff) ? print_number_llu_r(str, uvalue) :
+ print_number_lu_r(str, uvalue);
+ break;
+ case 8:
+ do {
+ *str++ = (char) ('0' + (uvalue % 10));
+ } while (uvalue /= 10);
+ break;
+ default:
+ fatal("Netdata supports only 32-bit & 64-bit systems.");
+ }
+
+ return str;
+}
+
+void buffer_print_llu(BUFFER *wb, unsigned long long uvalue)
+{
+ buffer_need_bytes(wb, 50);
+
+ char *str = &wb->buffer[wb->len];
+ char *wstr = str;
+
+ switch (sizeof(void *)) {
+ case 4:
+ wstr = (uvalue > (unsigned long long) 0xffffffff) ? print_number_llu_r(wstr, uvalue) :
+ print_number_lu_r(wstr, uvalue);
+ break;
+ case 8:
+ do {
+ *wstr++ = (char) ('0' + (uvalue % 10));
+ } while (uvalue /= 10);
+ break;
+ default:
+ fatal("Netdata supports only 32-bit & 64-bit systems.");
+ }
+
+ // terminate it
+ *wstr = '\0';
+
+ // reverse it
+ char *begin = str, *end = wstr - 1, aux;
+ while (end > begin) aux = *end, *end-- = *begin, *begin++ = aux;
+
+ // return the buffer length
+ wb->len += wstr - str;
+}
+
+void buffer_print_ll(BUFFER *wb, long long value)
+{
+ buffer_need_bytes(wb, 50);
+
+ if(value < 0) {
+ buffer_fast_strcat(wb, "-", 1);
+ value = -value;
+ }
+
+ buffer_print_llu(wb, value);
+}
+
+static unsigned char bits03_to_hex[16] = {
+ [0] = '0',
+ [1] = '1',
+ [2] = '2',
+ [3] = '3',
+ [4] = '4',
+ [5] = '5',
+ [6] = '6',
+ [7] = '7',
+ [8] = '8',
+ [9] = '9',
+ [10] = 'A',
+ [11] = 'B',
+ [12] = 'C',
+ [13] = 'D',
+ [14] = 'E',
+ [15] = 'F'
+};
+
+void buffer_print_llu_hex(BUFFER *wb, unsigned long long value)
+{
+ unsigned char buffer[sizeof(unsigned long long) * 2 + 2 + 1]; // 8 bytes * 2 + '0x' + '\0'
+ unsigned char *e = &buffer[sizeof(unsigned long long) * 2 + 2];
+ unsigned char *p = e;
+
+ *p-- = '\0';
+ *p-- = bits03_to_hex[value & 0xF];
+ value >>= 4;
+ if(value) {
+ *p-- = bits03_to_hex[value & 0xF];
+ value >>= 4;
+
+ while(value) {
+ *p-- = bits03_to_hex[value & 0xF];
+ value >>= 4;
+
+ if(value) {
+ *p-- = bits03_to_hex[value & 0xF];
+ value >>= 4;
+ }
+ }
+ }
+ *p-- = 'x';
+ *p = '0';
+
+ buffer_fast_strcat(wb, (char *)p, e - p);
+}
+
+void buffer_fast_strcat(BUFFER *wb, const char *txt, size_t len) {
+ if(unlikely(!txt || !*txt)) return;
+
+ buffer_need_bytes(wb, len + 1);
+
+ char *s = &wb->buffer[wb->len];
+ const char *end = &txt[len + 1];
+
+ while(txt != end)
+ *s++ = *txt++;
+
+ wb->len += len;
+
+ // keep it NULL terminating
+ // not counting it at wb->len
+ wb->buffer[wb->len] = '\0';
+}
+
+void buffer_strcat(BUFFER *wb, const char *txt)
+{
+ // buffer_sprintf(wb, "%s", txt);
+
+ if(unlikely(!txt || !*txt)) return;
+
+ buffer_need_bytes(wb, 1);
+
+ char *s = &wb->buffer[wb->len], *start, *end = &wb->buffer[wb->size];
+ size_t len = wb->len;
+
+ start = s;
+ while(*txt && s != end)
+ *s++ = *txt++;
+
+ len += s - start;
+
+ wb->len = len;
+ buffer_overflow_check(wb);
+
+ if(*txt) {
+ debug(D_WEB_BUFFER, "strcat(): increasing web_buffer at position %zu, size = %zu\n", wb->len, wb->size);
+ len = strlen(txt);
+ buffer_fast_strcat(wb, txt, len);
+ }
+ else {
+ // terminate the string
+ // without increasing the length
+ buffer_need_bytes(wb, (size_t)1);
+ wb->buffer[wb->len] = '\0';
+ }
+}
+
+void buffer_strcat_jsonescape(BUFFER *wb, const char *txt)
+{
+ while(*txt) {
+ switch(*txt) {
+ case '\\':
+ buffer_need_bytes(wb, 2);
+ wb->buffer[wb->len++] = '\\';
+ wb->buffer[wb->len++] = '\\';
+ break;
+ case '"':
+ buffer_need_bytes(wb, 2);
+ wb->buffer[wb->len++] = '\\';
+ wb->buffer[wb->len++] = '"';
+ break;
+ default: {
+ buffer_need_bytes(wb, 1);
+ wb->buffer[wb->len++] = *txt;
+ }
+ }
+ txt++;
+ }
+
+ buffer_overflow_check(wb);
+}
+
+void buffer_strcat_htmlescape(BUFFER *wb, const char *txt)
+{
+ while(*txt) {
+ switch(*txt) {
+ case '&': buffer_strcat(wb, "&amp;"); break;
+ case '<': buffer_strcat(wb, "&lt;"); break;
+ case '>': buffer_strcat(wb, "&gt;"); break;
+ case '"': buffer_strcat(wb, "&quot;"); break;
+ case '/': buffer_strcat(wb, "&#x2F;"); break;
+ case '\'': buffer_strcat(wb, "&#x27;"); break;
+ default: {
+ buffer_need_bytes(wb, 1);
+ wb->buffer[wb->len++] = *txt;
+ }
+ }
+ txt++;
+ }
+
+ buffer_overflow_check(wb);
+}
+
+void buffer_snprintf(BUFFER *wb, size_t len, const char *fmt, ...)
+{
+ if(unlikely(!fmt || !*fmt)) return;
+
+ buffer_need_bytes(wb, len + 1);
+
+ va_list args;
+ va_start(args, fmt);
+ wb->len += vsnprintfz(&wb->buffer[wb->len], len, fmt, args);
+ va_end(args);
+
+ buffer_overflow_check(wb);
+
+ // the buffer is \0 terminated by vsnprintfz
+}
+
+void buffer_vsprintf(BUFFER *wb, const char *fmt, va_list args)
+{
+ if(unlikely(!fmt || !*fmt)) return;
+
+ size_t wrote = 0, need = 2, space_remaining = 0;
+
+ do {
+ need += space_remaining * 2;
+
+ debug(D_WEB_BUFFER, "web_buffer_sprintf(): increasing web_buffer at position %zu, size = %zu, by %zu bytes (wrote = %zu)\n", wb->len, wb->size, need, wrote);
+ buffer_need_bytes(wb, need);
+
+ space_remaining = wb->size - wb->len - 1;
+
+ wrote = (size_t) vsnprintfz(&wb->buffer[wb->len], space_remaining, fmt, args);
+
+ } while(wrote >= space_remaining);
+
+ wb->len += wrote;
+
+ // the buffer is \0 terminated by vsnprintf
+}
+
+void buffer_sprintf(BUFFER *wb, const char *fmt, ...)
+{
+ if(unlikely(!fmt || !*fmt)) return;
+
+ va_list args;
+ size_t wrote = 0, need = 2, space_remaining = 0;
+
+ do {
+ need += space_remaining * 2;
+
+ debug(D_WEB_BUFFER, "web_buffer_sprintf(): increasing web_buffer at position %zu, size = %zu, by %zu bytes (wrote = %zu)\n", wb->len, wb->size, need, wrote);
+ buffer_need_bytes(wb, need);
+
+ space_remaining = wb->size - wb->len - 1;
+
+ va_start(args, fmt);
+ wrote = (size_t) vsnprintfz(&wb->buffer[wb->len], space_remaining, fmt, args);
+ va_end(args);
+
+ } while(wrote >= space_remaining);
+
+ wb->len += wrote;
+
+ // the buffer is \0 terminated by vsnprintf
+}
+
+
+void buffer_rrd_value(BUFFER *wb, NETDATA_DOUBLE value)
+{
+ buffer_need_bytes(wb, 50);
+
+ if(isnan(value) || isinf(value)) {
+ buffer_strcat(wb, "null");
+ 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);
+}
+
+// generate a javascript date, the fastest possible way...
+void buffer_jsdate(BUFFER *wb, int year, int month, int day, int hours, int minutes, int seconds)
+{
+ // 10 20 30 = 35
+ // 01234567890123456789012345678901234
+ // Date(2014,04,01,03,28,20)
+
+ buffer_need_bytes(wb, 30);
+
+ char *b = &wb->buffer[wb->len], *p;
+ unsigned int *q = (unsigned int *)b;
+
+ #if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ *q++ = 0x65746144; // "Date" backwards.
+ #else
+ *q++ = 0x44617465; // "Date"
+ #endif
+ p = (char *)q;
+
+ *p++ = '(';
+ *p++ = '0' + year / 1000; year %= 1000;
+ *p++ = '0' + year / 100; year %= 100;
+ *p++ = '0' + year / 10;
+ *p++ = '0' + year % 10;
+ *p++ = ',';
+ *p = '0' + month / 10; if (*p != '0') p++;
+ *p++ = '0' + month % 10;
+ *p++ = ',';
+ *p = '0' + day / 10; if (*p != '0') p++;
+ *p++ = '0' + day % 10;
+ *p++ = ',';
+ *p = '0' + hours / 10; if (*p != '0') p++;
+ *p++ = '0' + hours % 10;
+ *p++ = ',';
+ *p = '0' + minutes / 10; if (*p != '0') p++;
+ *p++ = '0' + minutes % 10;
+ *p++ = ',';
+ *p = '0' + seconds / 10; if (*p != '0') p++;
+ *p++ = '0' + seconds % 10;
+
+ unsigned short *r = (unsigned short *)p;
+
+#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
+ *r++ = 0x0029; // ")\0" backwards.
+ #else
+ *r++ = 0x2900; // ")\0"
+ #endif
+
+ wb->len += (size_t)((char *)r - b - 1);
+
+ // terminate it
+ wb->buffer[wb->len] = '\0';
+ buffer_overflow_check(wb);
+}
+
+// generate a date, the fastest possible way...
+void buffer_date(BUFFER *wb, int year, int month, int day, int hours, int minutes, int seconds)
+{
+ // 10 20 30 = 35
+ // 01234567890123456789012345678901234
+ // 2014-04-01 03:28:20
+
+ buffer_need_bytes(wb, 36);
+
+ char *b = &wb->buffer[wb->len];
+ char *p = b;
+
+ *p++ = '0' + year / 1000; year %= 1000;
+ *p++ = '0' + year / 100; year %= 100;
+ *p++ = '0' + year / 10;
+ *p++ = '0' + year % 10;
+ *p++ = '-';
+ *p++ = '0' + month / 10;
+ *p++ = '0' + month % 10;
+ *p++ = '-';
+ *p++ = '0' + day / 10;
+ *p++ = '0' + day % 10;
+ *p++ = ' ';
+ *p++ = '0' + hours / 10;
+ *p++ = '0' + hours % 10;
+ *p++ = ':';
+ *p++ = '0' + minutes / 10;
+ *p++ = '0' + minutes % 10;
+ *p++ = ':';
+ *p++ = '0' + seconds / 10;
+ *p++ = '0' + seconds % 10;
+ *p = '\0';
+
+ wb->len += (size_t)(p - b);
+
+ // terminate it
+ wb->buffer[wb->len] = '\0';
+ buffer_overflow_check(wb);
+}
+
+BUFFER *buffer_create(size_t size)
+{
+ BUFFER *b;
+
+ debug(D_WEB_BUFFER, "Creating new web buffer of size %zu.", size);
+
+ b = callocz(1, sizeof(BUFFER));
+ b->buffer = mallocz(size + sizeof(BUFFER_OVERFLOW_EOF) + 2);
+ b->buffer[0] = '\0';
+ b->size = size;
+ b->contenttype = CT_TEXT_PLAIN;
+ buffer_overflow_init(b);
+ buffer_overflow_check(b);
+
+ return(b);
+}
+
+void buffer_free(BUFFER *b) {
+ if(unlikely(!b)) return;
+
+ buffer_overflow_check(b);
+
+ debug(D_WEB_BUFFER, "Freeing web buffer of size %zu.", b->size);
+
+ freez(b->buffer);
+ freez(b);
+}
+
+void buffer_increase(BUFFER *b, size_t free_size_required) {
+ buffer_overflow_check(b);
+
+ size_t left = b->size - b->len;
+ if(left >= free_size_required) return;
+
+ size_t wanted = free_size_required - left;
+ size_t minimum = WEB_DATA_LENGTH_INCREASE_STEP;
+ if(minimum > wanted) wanted = minimum;
+
+ size_t optimal = b->size;
+ if(b->size > 5*1024*1024) optimal = b->size / 2;
+
+ if(optimal > wanted) wanted = optimal;
+
+ debug(D_WEB_BUFFER, "Increasing data buffer from size %zu to %zu.", b->size, b->size + wanted);
+
+ b->buffer = reallocz(b->buffer, b->size + wanted + sizeof(BUFFER_OVERFLOW_EOF) + 2);
+ b->size += wanted;
+
+ buffer_overflow_init(b);
+ buffer_overflow_check(b);
+}
diff --git a/libnetdata/buffer/buffer.h b/libnetdata/buffer/buffer.h
new file mode 100644
index 0000000..ce6f528
--- /dev/null
+++ b/libnetdata/buffer/buffer.h
@@ -0,0 +1,89 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_WEB_BUFFER_H
+#define NETDATA_WEB_BUFFER_H 1
+
+#include "../libnetdata.h"
+
+#define WEB_DATA_LENGTH_INCREASE_STEP 1024
+
+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
+} 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
+
+#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)
+
+#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);
+
+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);
+
+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);
+
+BUFFER *buffer_create(size_t size);
+void buffer_free(BUFFER *b);
+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);
+
+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);
+}
+
+#endif /* NETDATA_WEB_BUFFER_H */
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