Added virtual bytes pipe for mempool graph.

Added decimals to mempool graph y-axis.
fixes #14
fixes #12

frontend/src/app/shared/pipes/bytes-pipe/vbytes.pipe.ts

@@ -0,0 +1,63 @@
+/* tslint:disable */
+import { Pipe, PipeTransform } from '@angular/core';
+import { isNumberFinite, isPositive, isInteger, toDecimal } from './utils';
+
+export type ByteUnit = 'vB' | 'kvB' | 'MvB' | 'GvB' | 'TvB';
+
+@Pipe({
+    name: 'vbytes'
+})
+export class VbytesPipe implements PipeTransform {
+
+    static formats: { [key: string]: { max: number, prev?: ByteUnit } } = {
+        'vB': {max: 1000},
+        'kvB': {max: Math.pow(1000, 2), prev: 'vB'},
+        'MvB': {max: Math.pow(1000, 3), prev: 'kvB'},
+        'GvB': {max: Math.pow(1000, 4), prev: 'MvB'},
+        'TvB': {max: Number.MAX_SAFE_INTEGER, prev: 'GvB'}
+    };
+
+    transform(input: any, decimal: number = 0, from: ByteUnit = 'vB', to?: ByteUnit): any {
+
+        if (!(isNumberFinite(input) &&
+                isNumberFinite(decimal) &&
+                isInteger(decimal) &&
+                isPositive(decimal))) {
+            return input;
+        }
+
+        let bytes = input;
+        let unit = from;
+        while (unit !== 'vB') {
+            bytes *= 1024;
+            unit = VbytesPipe.formats[unit].prev!;
+        }
+
+        if (to) {
+            const format = VbytesPipe.formats[to];
+
+            const result = toDecimal(VbytesPipe.calculateResult(format, bytes), decimal);
+
+            return VbytesPipe.formatResult(result, to);
+        }
+
+        for (const key in VbytesPipe.formats) {
+            const format = VbytesPipe.formats[key];
+            if (bytes < format.max) {
+
+                const result = toDecimal(VbytesPipe.calculateResult(format, bytes), decimal);
+
+                return VbytesPipe.formatResult(result, key);
+            }
+        }
+    }
+
+    static formatResult(result: number, unit: string): string {
+        return `${result} ${unit}`;
+    }
+
+    static calculateResult(format: { max: number, prev?: ByteUnit }, bytes: number) {
+        const prev = format.prev ? VbytesPipe.formats[format.prev] : undefined;
+        return prev ? bytes / prev.max : bytes;
+    }
+}

frontend/src/app/shared/shared.module.ts

@@ -3,6 +3,7 @@ import { CommonModule } from '@angular/common';
 import { NgbButtonsModule, NgbModalModule } from '@ng-bootstrap/ng-bootstrap';
 
 import { BytesPipe } from './pipes/bytes-pipe/bytes.pipe';
+import { VbytesPipe } from './pipes/bytes-pipe/vbytes.pipe';
 import { RoundPipe } from './pipes/math-round-pipe/math-round.pipe';
 import { CeilPipe } from './pipes/math-ceil/math-ceil.pipe';
 import { ChartistComponent } from '../statistics/chartist.component';
@@ -18,17 +19,20 @@ import { ChartistComponent } from '../statistics/chartist.component';
     RoundPipe,
     CeilPipe,
     BytesPipe,
+    VbytesPipe,
   ],
   exports: [
     RoundPipe,
     CeilPipe,
     BytesPipe,
+    VbytesPipe,
     NgbButtonsModule,
     NgbModalModule,
     ChartistComponent,
   ],
   providers: [
-    BytesPipe
+    BytesPipe,
+    VbytesPipe,
   ]
 })
 export class SharedModule { }

frontend/src/app/statistics/statistics.component.ts

@@ -1,12 +1,12 @@
 import { Component, OnInit, LOCALE_ID, Inject } from '@angular/core';
 import { ApiService } from '../services/api.service';
 import { formatDate } from '@angular/common';
-import { BytesPipe } from '../shared/pipes/bytes-pipe/bytes.pipe';
+import { VbytesPipe } from '../shared/pipes/bytes-pipe/vbytes.pipe';
 
 import * as Chartist from 'chartist';
 import { FormGroup, FormBuilder } from '@angular/forms';
 import { IMempoolStats } from '../blockchain/interfaces';
-import { Subject, of, merge} from 'rxjs';
+import { of, merge} from 'rxjs';
 import { switchMap, tap } from 'rxjs/operators';
 import { ActivatedRoute } from '@angular/router';
 import { MemPoolService } from '../services/mem-pool.service';
@@ -34,7 +34,7 @@ export class StatisticsComponent implements OnInit {
   constructor(
     private apiService: ApiService,
     @Inject(LOCALE_ID) private locale: string,
-    private bytesPipe: BytesPipe,
+    private vbytesPipe: VbytesPipe,
     private formBuilder: FormBuilder,
     private route: ActivatedRoute,
     private memPoolService: MemPoolService,
@@ -77,7 +77,7 @@ export class StatisticsComponent implements OnInit {
       },
       axisY: {
         labelInterpolationFnc: (value: number): any => {
-          return this.bytesPipe.transform(value);
+          return this.vbytesPipe.transform(value, 2);
         },
         offset: 160
       },