Global: adds configurable trailing zeros for double formatting

Author: CarterLi

src/common/format.c

@@ -32,10 +32,10 @@ void ffFormatAppendFormatArg(FFstrbuf* buffer, const FFformatarg* formatarg)
             ffStrbufAppend(buffer, (const FFstrbuf*)formatarg->value);
             break;
         case FF_FORMAT_ARG_TYPE_FLOAT:
-            ffStrbufAppendDouble(buffer, *(float*)formatarg->value, instance.config.display.fractionNdigits);
+            ffStrbufAppendDouble(buffer, *(float*)formatarg->value, instance.config.display.fractionNdigits, instance.config.display.fractionTrailingZeros != FF_FRACTION_TRAILING_ZEROS_TYPE_HIDE);
             break;
         case FF_FORMAT_ARG_TYPE_DOUBLE:
-            ffStrbufAppendDouble(buffer, *(double*)formatarg->value, instance.config.display.fractionNdigits);
+            ffStrbufAppendDouble(buffer, *(double*)formatarg->value, instance.config.display.fractionNdigits, instance.config.display.fractionTrailingZeros != FF_FRACTION_TRAILING_ZEROS_TYPE_HIDE);
             break;
         case FF_FORMAT_ARG_TYPE_BOOL:
             ffStrbufAppendS(buffer, *(bool*)formatarg->value ? "true" : "false");

src/common/frequency.c

@@ -11,7 +11,7 @@ bool ffFreqAppendNum(uint32_t mhz, FFstrbuf* result)
 
     if (ndigits >= 0)
     {
-        ffStrbufAppendDouble(result, mhz / 1000., ndigits);
+        ffStrbufAppendDouble(result, mhz / 1000., ndigits, true);
         if (spaceBeforeUnit) ffStrbufAppendC(result, ' ');
         ffStrbufAppendS(result, "GHz");
     }

src/common/size.c

@@ -17,7 +17,7 @@ static void appendNum(FFstrbuf* result, uint64_t bytes, uint32_t base, const cha
     if (counter == 0)
         ffStrbufAppendUInt(result, bytes);
     else
-        ffStrbufAppendDouble(result, size, (int8_t) options->sizeNdigits);
+        ffStrbufAppendDouble(result, size, (int8_t) options->sizeNdigits, true);
     if (options->sizeSpaceBeforeUnit != FF_SPACE_BEFORE_UNIT_NEVER)
         ffStrbufAppendC(result, ' ');
     ffStrbufAppendS(result, prefixes[counter]);

src/options/display.c

@@ -380,6 +380,24 @@ const char* ffOptionsParseDisplayJsonConfig(FFOptionsDisplay* options, yyjson_va
                         return "display.fraction.ndigits must be an integer";
                     options->fractionNdigits = (int8_t) yyjson_get_int(ndigits);
                 }
+                yyjson_val* trailingZeros = yyjson_obj_get(val, "trailingZeros");
+                if (trailingZeros)
+                {
+                    if (yyjson_is_null(trailingZeros))
+                        options->fractionTrailingZeros = FF_FRACTION_TRAILING_ZEROS_TYPE_DEFAULT;
+                    else
+                    {
+                        int value;
+                        const char* error = ffJsonConfigParseEnum(trailingZeros, &value, (FFKeyValuePair[]) {
+                            { "default", FF_FRACTION_TRAILING_ZEROS_TYPE_DEFAULT },
+                            { "show", FF_FRACTION_TRAILING_ZEROS_TYPE_SHOW },
+                            { "hide", FF_FRACTION_TRAILING_ZEROS_TYPE_HIDE },
+                            {},
+                        });
+                        if (error) return error;
+                        options->fractionTrailingZeros = (FFFractionTrailingZerosType) value;
+                    }
+                }
             }
             else
                 return "display.fraction must be an object";
@@ -810,6 +828,7 @@ void ffOptionsInitDisplay(FFOptionsDisplay* options)
     options->freqNdigits = 2;
     options->freqSpaceBeforeUnit = FF_SPACE_BEFORE_UNIT_DEFAULT;
     options->fractionNdigits = -1;
+    options->fractionTrailingZeros = FF_FRACTION_TRAILING_ZEROS_TYPE_DEFAULT;
 
     ffListInit(&options->constants, sizeof(FFstrbuf));
 }

src/options/display.h

@@ -25,6 +25,13 @@ typedef enum __attribute__((__packed__)) FFSpaceBeforeUnitType
     FF_SPACE_BEFORE_UNIT_NEVER,
 } FFSpaceBeforeUnitType;
 
+typedef enum __attribute__((__packed__)) FFFractionTrailingZerosType
+{
+    FF_FRACTION_TRAILING_ZEROS_TYPE_DEFAULT,
+    FF_FRACTION_TRAILING_ZEROS_TYPE_SHOW,
+    FF_FRACTION_TRAILING_ZEROS_TYPE_HIDE,
+} FFFractionTrailingZerosType;
+
 typedef struct FFOptionsDisplay
 {
     //If one of those is empty, ffLogoPrint will set them
@@ -81,6 +88,7 @@ typedef struct FFOptionsDisplay
     int8_t freqNdigits;
     FFSpaceBeforeUnitType freqSpaceBeforeUnit;
     int8_t fractionNdigits;
+    FFFractionTrailingZerosType fractionTrailingZeros;
 
     FFlist constants; // list of FFstrbuf
 } FFOptionsDisplay;

src/util/FFstrbuf.c

@@ -571,7 +571,7 @@ void ffStrbufAppendUInt(FFstrbuf* strbuf, uint64_t value)
     strbuf->length += (uint32_t)(end - start);
 }
 
-void ffStrbufAppendDouble(FFstrbuf* strbuf, double value, int8_t precision)
+void ffStrbufAppendDouble(FFstrbuf* strbuf, double value, int8_t precision, bool trailingZeros)
 {
     assert(precision <= 15); // yyjson_write_number supports up to 15 digits after the decimal point
 
@@ -598,18 +598,29 @@ void ffStrbufAppendDouble(FFstrbuf* strbuf, double value, int8_t precision)
         return;
     }
 
-    if (precision > 1)
+    if (trailingZeros)
     {
-        for (char* p = end - 1; *p != '.' && p > start; --p)
-            --precision;
-        if (precision > 0)
-            ffStrbufAppendNC(strbuf, (uint32_t) precision, '0');
+        if (precision > 1)
+        {
+            for (char* p = end - 1; *p != '.' && p > start; --p)
+                --precision;
+            if (precision > 0)
+                ffStrbufAppendNC(strbuf, (uint32_t) precision, '0');
+        }
+        else if (precision == 0 || (precision < 0 && end[-1] == '0'))
+        {
+            goto removeDecimalPoint;
+        }
     }
-    else if (precision == 0 || (precision < 0 && end[-1] == '0'))
+    else
     {
-        // yyjson always appends ".0", so we need to remove it
-        strbuf->length -= 2;
-        strbuf->chars[strbuf->length] = '\0';
+        if (end[-1] == '0')
+        {
+        removeDecimalPoint:
+            // yyjson always appends ".0" to make it a float point number. We need to remove it
+            strbuf->length -= 2;
+            strbuf->chars[strbuf->length] = '\0';
+        }
     }
 }
 

src/util/FFstrbuf.h

@@ -107,7 +107,7 @@ void ffStrbufAppendSInt(FFstrbuf* strbuf, int64_t value);
 void ffStrbufAppendUInt(FFstrbuf* strbuf, uint64_t value);
 // Appends a double value to the string buffer with the specified precision (0~15).
 // if `precision < 0`, let yyjson decide the precision
-void ffStrbufAppendDouble(FFstrbuf* strbuf, double value, int8_t precision);
+void ffStrbufAppendDouble(FFstrbuf* strbuf, double value, int8_t precision, bool trailingZeros);
 
 FF_C_NODISCARD static inline FFstrbuf ffStrbufCreateA(uint32_t allocate)
 {