File.cpp

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// Copyright (c) 2013-2014 by Wayne C. Gramlich all rights reserved.

#include <assert.h>
#include <ctype.h>

#include "File.hpp"
#include "String.hpp"

// *File* routines:


unsigned int File__byte_read(File file) {
    int byte = fgetc(file);
    assert (byte >= 0);
    return (unsigned int)byte;
}


void File__byte_write(File file, unsigned int byte) {
    fputc(byte, file);
}


int File__character_read(File in_file) {
    return fgetc(in_file);
}


void File__close(File file) {
    assert (fclose(file) == 0);
}


double File__double_attribute_read(File in_file, String_Const attribute_name) {
    File__string_match(in_file, " ");
    File__string_match(in_file, attribute_name);
    File__string_match(in_file, "=\"");
    double fraction = (double)1.0;
    bool have_decimal_point = (bool)0;
    bool negative = (bool)0;
    double result = (double)0.0;
    while (1) {
        int character = File__character_read(in_file);
        if (isdigit(character)) {
            if (have_decimal_point) {
                fraction /= (double)10.0;
                result += fraction * (double)(character - '0');
            } else {
                result = result * 10.0 + (double)(character - '0');
            }
        } else if (character == '"') {
            break;
        } else if (character == '.') {
            have_decimal_point = (bool)1;
        } else if (character == '-') {
            negative = (bool)1;
        } else {
            assert(0);
        }
    }
    if (negative) {
        result = -result;
    }
    return result;
}


void File__format(File file, String_Const format, ...) {
    // Set up *variadic_arguments to start after *format*:
    va_list variadic_arguments;
    va_start(variadic_arguments, format);

    // Perform the format:
    unsigned int formatted_size = vfprintf(file, format, variadic_arguments);
}


float File__float_attribute_read(File in_file, String_Const attribute_name) {
    File__string_match(in_file, " ");
    File__string_match(in_file, attribute_name);
    File__string_match(in_file, "=\"");
    float fraction = (float)1.0;
    bool have_decimal_point = (bool)0;
    bool negative = (bool)0;
    float result = (float)0.0;
    while (1) {
        char character = File__character_read(in_file);
        if (isdigit(character)) {
            if (have_decimal_point) {
                fraction /= (float)10.0;
                result += fraction * (float)(character - '0');
            } else {
                result = result * 10.0 + (float)(character - '0');
            }
        } else if (character == '"') {
            break;
        } else if (character == '.') {
            have_decimal_point = (bool)1;
        } else if (character == '-') {
            negative = (bool)1;
        } else {
            assert(0);
        }
    }
    if (negative) {
        result = -result;
    }
    return result;
}


void File__flush(File file) {
    (void)fflush(file);
}



int File__integer_attribute_read(
  File in_file, String_Const attribute_name) {
    File__string_match(in_file, " ");
    File__string_match(in_file, attribute_name);
    File__string_match(in_file, "=\"");
    bool negative = (bool)0;
    int result = 0;
    while (1) {
        char character = File__character_read(in_file);
        if (isdigit(character)) {
            result = result * 10 + (character - '0');
        } else if (character == '"') {
            break;
        } else if (character == '-') {
            negative = (bool)1;
        } else {
            assert(0);
        }
    }
    if (negative) {
        result = -result;
    }
    return result;
}


unsigned int File__little_endian_short_read(File file) {
    int low_byte = fgetc(file);
    assert (low_byte >= 0);
    int high_byte = fgetc(file);
    assert (high_byte >= 0);
    unsigned int result = ((unsigned int)high_byte << 8) | (unsigned int)low_byte;
    return result;
}


void File__little_endian_short_write(File file, unsigned int xshort) {
    fputc(xshort & 0xff, file);
    fputc((xshort >> 8) & 0xff, file);
}


File File__open(String_Const file_name, String_Const flags) {
    return fopen(file_name, flags);
}


void File__string_match(File in_file, String_Const pattern) {
    unsigned int size = String__size(pattern);
    for (unsigned int index = 0; index < size; index++) {
        char character = File__character_read(in_file);
        assert(character == pattern[index]);
    }
}


void File__tag_match(File in_file, String_Const tag_name) {
    while (1) {
        char character = File__character_read(in_file);
        if (character == '<') {
            break;
        } else if (character == ' ') {
            // Do nothing:
        } else {
            assert(0);
        }
    }
    File__string_match(in_file, tag_name);
}