File: CharBuffer.cpp

package info (click to toggle)
libstatgen 1.0.15-8
  • links: PTS, VCS
  • area: main
  • in suites: forky, sid, trixie
  • size: 4,588 kB
  • sloc: cpp: 49,624; ansic: 1,408; makefile: 320; sh: 60
file content (165 lines) | stat: -rw-r--r-- 3,999 bytes parent folder | download | duplicates (4)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*
 *  Copyright (C) 2010  Regents of the University of Michigan
 *
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdlib.h>
#include "CharBuffer.h"

CharBuffer::CharBuffer()
    : myBuffer(NULL)
{
    myBuffer = (char *) malloc(DEFAULT_BUFFER_SIZE);
    myBufferAllocatedLen = DEFAULT_BUFFER_SIZE;
    reset();
}


CharBuffer::CharBuffer(int32_t initialSize)
    : myBuffer(NULL)
{
    myBuffer = (char *) malloc(initialSize);
    myBufferAllocatedLen = DEFAULT_BUFFER_SIZE;

    reset();
}


CharBuffer::~CharBuffer()
{
    reset();
    if(myBuffer != NULL)
    {
        free(myBuffer);
        myBuffer = NULL;
    }
}


// Copy Constructor   
CharBuffer::CharBuffer(const CharBuffer& buffer)
    : myBuffer(NULL)
{
    myBuffer = 
        (char *) malloc(DEFAULT_BUFFER_SIZE);
    myBufferAllocatedLen = DEFAULT_BUFFER_SIZE;

    reset();

    copy(buffer);
}


// Overload operator = to copy the passed in buffer into this buffer.
CharBuffer& CharBuffer::operator = (const CharBuffer& buffer)
{
    copy(buffer);
    return(*this);
}


// Overload operator = to copy the passed in buffer into this buffer.
CharBuffer& CharBuffer::operator = (const std::string& stringBuffer)
{
    // First check lengh
    if(prepareNewLength(stringBuffer.length()))
    {
        memcpy(myBuffer, stringBuffer.c_str(), stringBuffer.length());
    }
    // TODO: on failure of prepareNewLength, should it throw an exception?
    
    return(*this);
}


bool CharBuffer::copy(const CharBuffer& buffer)
{
    // Check to see if the passed in value is the same as this.
    if(this == &buffer)
    {
        return(true);
    }

    // Copy the buffer.
    // First check lengh
    prepareNewLength(buffer.myBufferLen);

    memcpy(myBuffer, buffer.myBuffer, buffer.myBufferLen);
    myBufferLen = buffer.myBufferLen;

    return(true);
}


// Reset the buffer for a new entry, clearing out previous values.
void CharBuffer::reset()
{
    myBufferLen = 0;
    if(myBuffer != NULL)
    {
        myBuffer[0] = 0;
    }
}


// Read from a file into the buffer.  length is the amount of data to read.
// Returns the number of bytes read.
int CharBuffer::readFromFile(IFILE filePtr, int32_t length)
{
    if(filePtr == NULL)
    {
        return(0);
    }

    if(prepareNewLength(length))
    {
        return(ifread(filePtr, myBuffer, length));
    }
    // failed to setup the buffer, return false.
    return(false);
}


// newLen is the new length that this buffer needs to be.
bool CharBuffer::prepareNewLength(int32_t newLen)
{
    if(newLen < 0)
    {
        // Invalid length.
        return(false);
    }
    
    // myBufferAllocatedLen must be bigger than new length, because the
    // newLen position is set to 0.
    if(myBufferAllocatedLen <= newLen)
    {
        // Not enough space is allocated, so allocate more space.
        char* tmpBufferPtr = (char *)realloc(myBuffer, newLen);
        if(tmpBufferPtr == NULL)
        {
            // FAILED to allocate memory
            fprintf(stderr, "FAILED TO ALLOCATE MEMORY!!!");
            // myStatus.addError(GlfStatus::FAIL_MEM, "Failed Memory Allocation.");
            return(false);
        }
        // Successfully allocated memory, so set myRecordPtr.
        myBuffer = tmpBufferPtr;
        myBufferAllocatedLen = newLen;
    }
    myBufferLen = newLen;
    myBuffer[newLen] = 0;
    return(true);
}