make2/factory_sliceing/download_batch_data/utils/changeFiles.py

import os,time
import re
from download_batch_data.utils.logs import log


def changeMtlFile(localMtlPath,newName):
    beginTime = time.time()
    try:
        # 使用更高效的文件读取方式 [6,8](@ref)
        with open(localMtlPath, 'r', encoding='utf-8') as f:
            content = f.read()
        
        # 使用字符串方法直接查找和替换，避免不必要的循环 [9](@ref)
        lines = content.split('\n')
        for i, line in enumerate(lines):
            stripped_line = line.strip()
            if stripped_line.startswith('map_Kd '):
                lines[i] = f"map_Kd {newName}"
                break
        # 批量写入，减少I/O操作 [6](@ref)
        with open(localMtlPath, 'w', encoding='utf-8') as f:
            f.write('\n'.join(lines))
            
    except IOError as e:
        log(f"处理文件 {localMtlPath} 时出错: {e}")
        return False
    except UnicodeDecodeError as e:
        log(f"文件编码错误 {localMtlPath}: {e}")
        return False
    endTime = time.time()
    log(f"修改文件文件内容 {localMtlPath} : 耗时{endTime - beginTime}秒")
    return True




def changeObjFile(localObjPath,newName):
    beginTime = time.time()
    try:
        # 优化策略：mtllib通常在文件前几行，先只读取前100行
        # 对于大文件（如155万行），这样可以大幅减少内存使用和处理时间
        with open(localObjPath, 'r', encoding='utf-8') as f:
            first_100_lines = []
            mtllib_line_idx = -1
            
            # 读取前100行查找mtllib
            for i in range(100):
                line = f.readline()
                if not line:
                    break
                first_100_lines.append(line)
                if mtllib_line_idx == -1 and line.strip().startswith('mtllib '):
                    mtllib_line_idx = i
            
            # 如果在前100行找到了mtllib，直接修改
            if mtllib_line_idx != -1:
                parts = first_100_lines[mtllib_line_idx].split(' ', 1)
                if len(parts) > 1:
                    #old_mtl_name = parts[1].strip()
                    new_mtl_name = f"{newName}"
                    first_100_lines[mtllib_line_idx] = f"mtllib {new_mtl_name}\n"
                    # 读取剩余内容并合并
                    remaining_content = f.read()
                    # 写回文件
                    with open(localObjPath, 'w', encoding='utf-8') as f_out:
                        f_out.writelines(first_100_lines)
                        if remaining_content:
                            f_out.write(remaining_content)
                    
                    endTime = time.time()
                    log(f"修改文件文件内容 {localObjPath} : 耗时{endTime - beginTime}秒")
                    return True
            
            log(f"浪费时间读取完整的文件，进行替换mtllib路径, localObjPath={localObjPath}, newName={newName}")
            # 如果前100行没找到，读取整个文件（很少见的情况）
            f.seek(0)  # 重置文件指针
            content = f.read()
            # 使用正则表达式一次性替换（更高效）
            pattern = r'^mtllib\s+(.+)$'
            def replace_mtllib(match):
                old_mtl_name = match.group(1).strip()
                new_mtl_name = f"{newName}_{old_mtl_name}"
                return f"mtllib {new_mtl_name}"
            
            new_content = re.sub(pattern, replace_mtllib, content, flags=re.MULTILINE)
            if new_content != content:
                with open(localObjPath, 'w', encoding='utf-8') as f_out:
                    f_out.write(new_content)
                endTime = time.time()
                log(f"完整读取修改文件文件内容 {localObjPath} : 耗时{endTime - beginTime}秒")
                return True
            
    except IOError as e:
        print(f"处理文件 {localObjPath} 时出错: {e}")
        return False
    except UnicodeDecodeError as e:
        print(f"文件编码错误 {localObjPath}: {e}")
        return False
    
    return False