1 /****************************************************************************
2 * Copyright (C) 2014-2015 Intel Corporation. All Rights Reserved.
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5 * copy of this software and associated documentation files (the "Software"),
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9 * Software is furnished to do so, subject to the following conditions:
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11 * The above copyright notice and this permission notice (including the next
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13 * Software.
14 *
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16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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21 * IN THE SOFTWARE.
22 *
23 * @file knobs_init.h
24 *
25 * @brief Dynamic Knobs Initialization for Core.
26 *
27 ******************************************************************************/
28 #pragma once
29
30 #include <core/knobs.h>
31 #include <stdlib.h>
32 #include <string.h>
33 #include <ctype.h>
34 #include <stdio.h>
35
36 // Assume the type is compatible with a 32-bit integer
37 template <typename T>
ConvertEnvToKnob(const char * pOverride,T & knobValue)38 static inline void ConvertEnvToKnob(const char* pOverride, T& knobValue)
39 {
40 uint32_t value = 0;
41 char* pStopped = nullptr;
42 value = strtoul(pOverride, &pStopped, 0);
43 if (pStopped != pOverride)
44 {
45 knobValue = static_cast<T>(value);
46 }
47 }
48
ConvertEnvToKnob(const char * pOverride,bool & knobValue)49 static inline void ConvertEnvToKnob(const char* pOverride, bool& knobValue)
50 {
51 size_t len = strlen(pOverride);
52 if (len == 1)
53 {
54 auto c = tolower(pOverride[0]);
55 if (c == 'y' || c == 't' || c == '1')
56 {
57 knobValue = true;
58 return;
59 }
60 if (c == 'n' || c == 'f' || c == '0')
61 {
62 knobValue = false;
63 return;
64 }
65 }
66
67 // Try converting to a number and casting to bool
68 uint32_t value = 0;
69 char* pStopped = nullptr;
70 value = strtoul(pOverride, &pStopped, 0);
71 if (pStopped != pOverride)
72 {
73 knobValue = value != 0;
74 }
75 }
76
ConvertEnvToKnob(const char * pOverride,float & knobValue)77 static inline void ConvertEnvToKnob(const char* pOverride, float& knobValue)
78 {
79 float value = knobValue;
80 if (sscanf(pOverride, "%f", &value))
81 {
82 knobValue = value;
83 }
84 }
85
ConvertEnvToKnob(const char * pOverride,std::string & knobValue)86 static inline void ConvertEnvToKnob(const char* pOverride, std::string& knobValue)
87 {
88 knobValue = pOverride;
89 }
90
91 template <typename T>
InitKnob(T & knob)92 static inline void InitKnob(T& knob)
93 {
94 // Read environment variables
95 const char* pOverride = getenv(knob.Name());
96
97 if (pOverride)
98 {
99 auto knobValue = knob.DefaultValue();
100 ConvertEnvToKnob(pOverride, knobValue);
101 knob.Value(knobValue);
102 }
103 else
104 {
105 // Set default value
106 knob.Value(knob.DefaultValue());
107 }
108 }
109