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authorFederico Ceratto <federico.ceratto@gmail.com>2016-03-30 21:40:42 +0000
committerFederico Ceratto <federico.ceratto@gmail.com>2016-03-30 21:40:42 +0000
commit9ce153ce7167c11adba8ac225edc7a707e97c6eb (patch)
tree9f6e849cce2dcc7e5b4e9e6252c843dc2d0787a2 /src/storage_number.c
downloadnetdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.tar.xz
netdata-9ce153ce7167c11adba8ac225edc7a707e97c6eb.zip
Imported Upstream version 1.0.0upstream/1.0.0
Diffstat (limited to 'src/storage_number.c')
-rwxr-xr-xsrc/storage_number.c206
1 files changed, 206 insertions, 0 deletions
diff --git a/src/storage_number.c b/src/storage_number.c
new file mode 100755
index 000000000..225cf0348
--- /dev/null
+++ b/src/storage_number.c
@@ -0,0 +1,206 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+#ifdef STORAGE_WITH_MATH
+#include <math.h>
+#endif
+
+#include "common.h"
+#include "log.h"
+#include "storage_number.h"
+
+#if __GNUC__
+#if __x86_64__ || __ppc64__
+#define ENVIRONMENT64
+#else
+#define ENVIRONMENT32
+#endif
+#endif
+
+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) 0-6 (7 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) {
+ error("Number " CALCULATED_NUMBER_FORMAT " is too big.", value);
+ 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;
+}
+
+#ifdef ENVIRONMENT32
+// This trick seems to give an 80% speed increase in 32bit systems
+// print_calculated_number_llu_r() will just print the digits up to the
+// point the remaining value fits in 32 bits, and then calls
+// print_calculated_number_lu_r() to print the rest with 32 bit arithmetic.
+
+static char *print_calculated_number_lu_r(char *str, unsigned long uvalue) {
+ char *wstr = str;
+
+ // print each digit
+ do *wstr++ = (char)(48 + (uvalue % 10)); while(uvalue /= 10);
+ return wstr;
+}
+
+static char *print_calculated_number_llu_r(char *str, unsigned long long uvalue) {
+ char *wstr = str;
+
+ // print each digit
+ do *wstr++ = (char)(48 + (uvalue % 10)); while((uvalue /= 10) && uvalue > (unsigned long long)0xffffffff);
+ if(uvalue) return print_calculated_number_lu_r(wstr, uvalue);
+ return wstr;
+}
+#endif
+
+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 llrint() there are rounding problems
+ // for example 0.9 becomes 0.89
+ unsigned long long uvalue = (unsigned long long int) llrint(value * (calculated_number)100000);
+#else
+ unsigned long long uvalue = value * (calculated_number)100000;
+#endif
+
+#ifdef ENVIRONMENT32
+ if(uvalue > (unsigned long long)0xffffffff)
+ wstr = print_calculated_number_llu_r(str, uvalue);
+ else
+ wstr = print_calculated_number_lu_r(str, uvalue);
+#else
+ do *wstr++ = (char)(48 + (uvalue % 10)); while(uvalue /= 10);
+#endif
+
+ // 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 );
+}