modularized all source code (#4391)

* modularized all external plugins

* added README.md in plugins

* fixed title

* fixed typo

* relative link to external plugins

* external plugins configuration README

* added plugins link

* remove plugins link

* plugin names are links

* added links to external plugins

* removed unecessary spacing

* list to table

* added language

* fixed typo

* list to table on internal plugins

* added more documentation to internal plugins

* moved python, node, and bash code and configs into the external plugins

* added statsd README

* fix bug with corrupting config.h every 2nd compilation

* moved all config files together with their code

* more documentation

* diskspace info

* fixed broken links in apps.plugin

* added backends docs

* updated plugins readme

* move nc-backend.sh to backends

* created daemon directory

* moved all code outside src/

* fixed readme identation

* renamed plugins.d.plugin to plugins.d

* updated readme

* removed linux- from linux plugins

* updated readme

* updated readme

* updated readme

* updated readme

* updated readme

* updated readme

* fixed README.md links

* fixed netdata tree links

* updated codacy, codeclimate and lgtm excluded paths

* update CMakeLists.txt

* updated automake options at top directory

* libnetdata slit into directories

* updated READMEs

* updated READMEs

* updated ARL docs

* updated ARL docs

* moved /plugins to /collectors

* moved all external plugins outside plugins.d

* updated codacy, codeclimate, lgtm

* updated README

* updated url

* updated readme

* updated readme

* updated readme

* updated readme

* moved api and web into webserver

* web/api web/gui web/server

* modularized webserver

* removed web/gui/version.txt

4 files changed, 334 insertions, 0 deletions

diff --git a/libnetdata/storage_number/Makefile.am b/libnetdata/storage_number/Makefile.am
new file mode 100644
index 0000000000..1cb69ed99a
--- /dev/null
+++ b/libnetdata/storage_number/Makefile.am
@@ -0,0 +1,9 @@
+# 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/storage_number/README.md b/libnetdata/storage_number/README.md
new file mode 100644
index 0000000000..e69de29bb2
--- /dev/null
+++ b/libnetdata/storage_number/README.md
diff --git a/libnetdata/storage_number/storage_number.c b/libnetdata/storage_number/storage_number.c
new file mode 100644
index 0000000000..db4cb700b4
--- /dev/null
+++ b/libnetdata/storage_number/storage_number.c
@@ -0,0 +1,233 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "../libnetdata.h"
+
+storage_number pack_storage_number(calculated_number value, uint32_t flags)
+{
+    // bit 32 = sign 0:positive, 1:negative
+    // bit 31 = 0:divide, 1:multiply
+    // bit 30, 29, 28 = (multiplier or divider) 0-7 (8 total)
+    // bit 27, 26, 25 flags
+    // bit 24 to bit 1 = the value
+
+    storage_number r = get_storage_number_flags(flags);
+    if(!value) return r;
+
+    int m = 0;
+    calculated_number n = value;
+
+    // if the value is negative
+    // add the sign bit and make it positive
+    if(n < 0) {
+        r += (1 << 31); // the sign bit 32
+        n = -n;
+    }
+
+    // make its integer part fit in 0x00ffffff
+    // by dividing it by 10 up to 7 times
+    // and increasing the multiplier
+    while(m < 7 && n > (calculated_number)0x00ffffff) {
+        n /= 10;
+        m++;
+    }
+
+    if(m) {
+        // the value was too big and we divided it
+        // so we add a multiplier to unpack it
+        r += (1 << 30) + (m << 27); // the multiplier m
+
+        if(n > (calculated_number)0x00ffffff) {
+            #ifdef NETDATA_INTERNAL_CHECKS
+            error("Number " CALCULATED_NUMBER_FORMAT " is too big.", value);
+            #endif
+            r += 0x00ffffff;
+            return r;
+        }
+    }
+    else {
+        // 0x0019999e is the number that can be multiplied
+        // by 10 to give 0x00ffffff
+        // while the value is below 0x0019999e we can
+        // multiply it by 10, up to 7 times, increasing
+        // the multiplier
+        while(m < 7 && n < (calculated_number)0x0019999e) {
+            n *= 10;
+            m++;
+        }
+
+        // the value was small enough and we multiplied it
+        // so we add a divider to unpack it
+        r += (0 << 30) + (m << 27); // the divider m
+    }
+
+#ifdef STORAGE_WITH_MATH
+    // without this there are rounding problems
+    // example: 0.9 becomes 0.89
+    r += lrint((double) n);
+#else
+    r += (storage_number)n;
+#endif
+
+    return r;
+}
+
+calculated_number unpack_storage_number(storage_number value)
+{
+    if(!value) return 0;
+
+    int sign = 0, exp = 0;
+
+    value ^= get_storage_number_flags(value);
+
+    if(value & (1 << 31)) {
+        sign = 1;
+        value ^= 1 << 31;
+    }
+
+    if(value & (1 << 30)) {
+        exp = 1;
+        value ^= 1 << 30;
+    }
+
+    int mul = value >> 27;
+    value ^= mul << 27;
+
+    calculated_number n = value;
+
+    // fprintf(stderr, "UNPACK: %08X, sign = %d, exp = %d, mul = %d, n = " CALCULATED_NUMBER_FORMAT "\n", value, sign, exp, mul, n);
+
+    while(mul > 0) {
+        if(exp) n *= 10;
+        else n /= 10;
+        mul--;
+    }
+
+    if(sign) n = -n;
+    return n;
+}
+
+/*
+int print_calculated_number(char *str, calculated_number value)
+{
+    char *wstr = str;
+
+    int sign = (value < 0) ? 1 : 0;
+    if(sign) value = -value;
+
+#ifdef STORAGE_WITH_MATH
+    // without llrintl() there are rounding problems
+    // for example 0.9 becomes 0.89
+    unsigned long long uvalue = (unsigned long long int) llrintl(value * (calculated_number)100000);
+#else
+    unsigned long long uvalue = value * (calculated_number)100000;
+#endif
+
+    wstr = print_number_llu_r_smart(str, uvalue);
+
+    // make sure we have 6 bytes at least
+    while((wstr - str) < 6) *wstr++ = '0';
+
+    // put the sign back
+    if(sign) *wstr++ = '-';
+
+    // reverse it
+    char *begin = str, *end = --wstr, aux;
+    while (end > begin) aux = *end, *end-- = *begin, *begin++ = aux;
+    // wstr--;
+    // strreverse(str, wstr);
+
+    // remove trailing zeros
+    int decimal = 5;
+    while(decimal > 0 && *wstr == '0') {
+        *wstr-- = '\0';
+        decimal--;
+    }
+
+    // terminate it, one position to the right
+    // to let space for a dot
+    wstr[2] = '\0';
+
+    // make space for the dot
+    int i;
+    for(i = 0; i < decimal ;i++) {
+        wstr[1] = wstr[0];
+        wstr--;
+    }
+
+    // put the dot
+    if(wstr[2] == '\0') { wstr[1] = '\0'; decimal--; }
+    else wstr[1] = '.';
+
+    // return the buffer length
+    return (int) ((wstr - str) + 2 + decimal );
+}
+*/
+
+int print_calculated_number(char *str, calculated_number value) {
+    // info("printing number " CALCULATED_NUMBER_FORMAT, value);
+    char integral_str[50], fractional_str[50];
+
+    char *wstr = str;
+
+    if(unlikely(value < 0)) {
+        *wstr++ = '-';
+        value = -value;
+    }
+
+    calculated_number integral, fractional;
+
+#ifdef STORAGE_WITH_MATH
+    fractional = calculated_number_modf(value, &integral) * 10000000.0;
+#else
+    fractional = ((unsigned long long)(value * 10000000ULL) % 10000000ULL);
+#endif
+
+    unsigned long long integral_int = (unsigned long long)integral;
+    unsigned long long fractional_int = (unsigned long long)calculated_number_llrint(fractional);
+    if(unlikely(fractional_int >= 10000000)) {
+        integral_int += 1;
+        fractional_int -= 10000000;
+    }
+
+    // info("integral " CALCULATED_NUMBER_FORMAT " (%llu), fractional " CALCULATED_NUMBER_FORMAT " (%llu)", integral, integral_int, fractional, fractional_int);
+
+    char *istre;
+    if(unlikely(integral_int == 0)) {
+        integral_str[0] = '0';
+        istre = &integral_str[1];
+    }
+    else
+        // convert the integral part to string (reversed)
+        istre = print_number_llu_r_smart(integral_str, integral_int);
+
+    // copy reversed the integral string
+    istre--;
+    while( istre >= integral_str ) *wstr++ = *istre--;
+
+    if(likely(fractional_int != 0)) {
+        // add a dot
+        *wstr++ = '.';
+
+        // convert the fractional part to string (reversed)
+        char *fstre = print_number_llu_r_smart(fractional_str, fractional_int);
+
+        // prepend zeros to reach 7 digits length
+        int decimal = 7;
+        int len = (int)(fstre - fractional_str);
+        while(len < decimal) {
+            *wstr++ = '0';
+            len++;
+        }
+
+        char *begin = fractional_str;
+        while(begin < fstre && *begin == '0') begin++;
+
+        // copy reversed the fractional string
+        fstre--;
+        while( fstre >= begin ) *wstr++ = *fstre--;
+    }
+
+    *wstr = '\0';
+    // info("printed number '%s'", str);
+    return (int)(wstr - str);
+}
diff --git a/libnetdata/storage_number/storage_number.h b/libnetdata/storage_number/storage_number.h
new file mode 100644
index 0000000000..5353ab60b9
--- /dev/null
+++ b/libnetdata/storage_number/storage_number.h
@@ -0,0 +1,92 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#ifndef NETDATA_STORAGE_NUMBER_H
+#define NETDATA_STORAGE_NUMBER_H 1
+
+#include "../libnetdata.h"
+
+#ifdef NETDATA_WITHOUT_LONG_DOUBLE
+
+#define powl pow
+#define modfl modf
+#define llrintl llrint
+#define roundl round
+#define sqrtl sqrt
+#define copysignl copysign
+#define strtold strtod
+
+typedef double calculated_number;
+#define CALCULATED_NUMBER_FORMAT "%0.7f"
+#define CALCULATED_NUMBER_FORMAT_ZERO "%0.0f"
+#define CALCULATED_NUMBER_FORMAT_AUTO "%f"
+
+#define LONG_DOUBLE_MODIFIER "f"
+typedef double LONG_DOUBLE;
+
+#else
+
+typedef long double calculated_number;
+#define CALCULATED_NUMBER_FORMAT "%0.7Lf"
+#define CALCULATED_NUMBER_FORMAT_ZERO "%0.0Lf"
+#define CALCULATED_NUMBER_FORMAT_AUTO "%Lf"
+
+#define LONG_DOUBLE_MODIFIER "Lf"
+typedef long double LONG_DOUBLE;
+
+#endif
+
+//typedef long long calculated_number;
+//#define CALCULATED_NUMBER_FORMAT "%lld"
+
+typedef long long collected_number;
+#define COLLECTED_NUMBER_FORMAT "%lld"
+
+/*
+typedef long double collected_number;
+#define COLLECTED_NUMBER_FORMAT "%0.7Lf"
+*/
+
+#define calculated_number_modf(x, y) modfl(x, y)
+#define calculated_number_llrint(x) llrintl(x)
+#define calculated_number_round(x) roundl(x)
+#define calculated_number_fabs(x) fabsl(x)
+#define calculated_number_epsilon (calculated_number)0.0000001
+
+#define calculated_number_equal(a, b) (calculated_number_fabs((a) - (b)) < calculated_number_epsilon)
+
+typedef uint32_t storage_number;
+#define STORAGE_NUMBER_FORMAT "%u"
+
+#define SN_NOT_EXISTS       (0x0 << 24)
+#define SN_EXISTS           (0x1 << 24)
+#define SN_EXISTS_RESET     (0x2 << 24)
+#define SN_EXISTS_UNDEF1    (0x3 << 24)
+#define SN_EXISTS_UNDEF2    (0x4 << 24)
+#define SN_EXISTS_UNDEF3    (0x5 << 24)
+#define SN_EXISTS_UNDEF4    (0x6 << 24)
+
+#define SN_FLAGS_MASK       (~(0x6 << 24))
+
+// extract the flags
+#define get_storage_number_flags(value) ((((storage_number)(value)) & (1 << 24)) | (((storage_number)(value)) & (2 << 24)) | (((storage_number)(value)) & (4 << 24)))
+#define SN_EMPTY_SLOT 0x00000000
+
+// checks
+#define does_storage_number_exist(value) ((get_storage_number_flags(value) != 0)?1:0)
+#define did_storage_number_reset(value)  ((get_storage_number_flags(value) == SN_EXISTS_RESET)?1:0)
+
+storage_number pack_storage_number(calculated_number value, uint32_t flags);
+calculated_number unpack_storage_number(storage_number value);
+
+int print_calculated_number(char *str, calculated_number value);
+
+#define STORAGE_NUMBER_POSITIVE_MAX (167772150000000.0)
+#define STORAGE_NUMBER_POSITIVE_MIN (0.0000001)
+#define STORAGE_NUMBER_NEGATIVE_MAX (-0.0000001)
+#define STORAGE_NUMBER_NEGATIVE_MIN (-167772150000000.0)
+
+// accepted accuracy loss
+#define ACCURACY_LOSS 0.0001
+#define accuracy_loss(t1, t2) (((t1) == (t2) || (t1) == 0.0 || (t2) == 0.0) ? 0.0 : (100.0 - (((t1) > (t2)) ? ((t2) * 100.0 / (t1) ) : ((t1) * 100.0 / (t2)))))
+
+#endif /* NETDATA_STORAGE_NUMBER_H */