ucx: src/buffer.c@af6be1e123aa (annotated)

src/buffer.c@af6be1e123aa (annotated)

src/buffer.c

Tue, 28 Dec 2021 17:38:02 +0100

author: Mike Becker <universe@uap-core.de>
date: Tue, 28 Dec 2021 17:38:02 +0100
changeset 489: af6be1e123aa
parent 483: 929016224c3c
child 500: eb9e7bd40a8e
permissions: -rw-r--r--

add some const qualifiers

 /*
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
  *
  * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
  *
  *   1. Redistributions of source code must retain the above copyright
  *      notice, this list of conditions and the following disclaimer.
  *
  *   2. Redistributions in binary form must reproduce the above copyright
  *      notice, this list of conditions and the following disclaimer in the
  *      documentation and/or other materials provided with the distribution.
  *
  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  * POSSIBILITY OF SUCH DAMAGE.
  */
 #include "cx/buffer.h"
 #include "cx/utils.h"
 #include <stdlib.h>
 #include <string.h>
 CxBuffer cxBufferCreate(
         void *space,
         size_t capacity,
         int flags
 ) {
     CxBuffer buffer = (CxBuffer) malloc(sizeof(cx_buffer_s));
     if (buffer) {
         buffer->flags = flags;
         if (!space) {
             buffer->bytes = malloc(capacity);
             if (!buffer->bytes) {
                 free(buffer);
                 return NULL;
             }
             memset(buffer->bytes, 0, capacity);
             buffer->flags |= CX_BUFFER_FREE_CONTENTS;
         } else {
             buffer->bytes = space;
         }
         buffer->capacity = capacity;
         buffer->size = 0;
         buffer->pos = 0;
     }
     return buffer;
 }
 void cxBufferDestroy(CxBuffer buffer) {
     if ((buffer->flags & CX_BUFFER_FREE_CONTENTS) == CX_BUFFER_FREE_CONTENTS) {
         free(buffer->bytes);
     }
     free(buffer);
 }
 CxBuffer cxBufferExtract(
         CxBuffer src,
         size_t start,
         size_t length,
         int flags
 ) {
     if (src->size == 0 || length == 0 ||
         ((size_t) -1) - start < length || start + length > src->capacity) {
         return NULL;
     }
     CxBuffer dst = (CxBuffer) malloc(sizeof(cx_buffer_s));
     if (dst) {
         dst->bytes = malloc(length);
         if (!dst->bytes) {
             free(dst);
             return NULL;
         }
         dst->capacity = length;
         dst->size = length;
         dst->flags = flags | CX_BUFFER_FREE_CONTENTS;
         dst->pos = 0;
         memcpy(dst->bytes, src->bytes + start, length);
     }
     return dst;
 }
 int cxBufferSeek(
         CxBuffer buffer,
         off_t offset,
         int whence
 ) {
     size_t npos;
     switch (whence) {
         case SEEK_CUR:
             npos = buffer->pos;
             break;
         case SEEK_END:
             npos = buffer->size;
             break;
         case SEEK_SET:
             npos = 0;
             break;
         default:
             return -1;
     }
     size_t opos = npos;
     npos += offset;
     if ((offset > 0 && npos < opos) || (offset < 0 && npos > opos)) {
         return -1;
     }
     if (npos >= buffer->size) {
         return -1;
     } else {
         buffer->pos = npos;
         return 0;
     }
 }
 int cxBufferEof(CxBuffer buffer) {
     return buffer->pos >= buffer->size;
 }
 int cxBufferMinimumCapacity(
         CxBuffer buffer,
         size_t additional_bytes
 ) {
     size_t newcap = buffer->capacity + additional_bytes;
     // overflow protection
     if (newcap < buffer->capacity) {
         return -1;
     }
     unsigned char *newspace = realloc(buffer->bytes, newcap);
     if (newspace) {
         memset(newspace + buffer->size, 0, newcap - buffer->size);
         buffer->bytes = newspace;
         buffer->capacity = newcap;
     } else {
         return -1;
     }
     return 0;
 }
 size_t cxBufferWrite(
         void const *ptr,
         size_t size,
         size_t nitems,
         CxBuffer buffer
 ) {
     size_t len;
     if (cx_szmul(size, nitems, &len)) {
         return 0;
     }
     size_t required = buffer->pos + len;
     if (buffer->pos > required) {
         return 0;
     }
     if (required > buffer->capacity) {
         if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
             if (cxBufferMinimumCapacity(buffer, required)) {
                 return 0;
             }
         } else {
             len = buffer->capacity - buffer->pos;
             if (size > 1) {
                 len -= len % size;
             }
         }
     }
     if (len == 0) {
         return len;
     }
     memcpy(buffer->bytes + buffer->pos, ptr, len);
     buffer->pos += len;
     if (buffer->pos > buffer->size) {
         buffer->size = buffer->pos;
     }
     return len / size;
 }
 size_t cxBufferRead(
         void *ptr,
         size_t size,
         size_t nitems,
         CxBuffer buffer
 ) {
     size_t len;
     if (cx_szmul(size, nitems, &len)) {
         return 0;
     }
     if (buffer->pos + len > buffer->size) {
         len = buffer->size - buffer->pos;
         if (size > 1) len -= len % size;
     }
     if (len <= 0) {
         return len;
     }
     memcpy(ptr, buffer->bytes + buffer->pos, len);
     buffer->pos += len;
     return len / size;
 }
 int cxBufferPut(
         CxBuffer buffer,
         int c
 ) {
     if (buffer->pos >= buffer->capacity) {
         if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
             if (cxBufferMinimumCapacity(buffer, buffer->capacity + 1)) {
                 return EOF;
             }
         } else {
             return EOF;
         }
     }
     c &= 0xFF;
     buffer->bytes[buffer->pos] = (unsigned char) c;
     buffer->pos++;
     if (buffer->pos > buffer->size) {
         buffer->size = buffer->pos;
     }
     return c;
 }
 int cxBufferGet(CxBuffer buffer) {
     if (cxBufferEof(buffer)) {
         return EOF;
     } else {
         int c = buffer->bytes[buffer->pos];
         buffer->pos++;
         return c;
     }
 }
 size_t cxBufferPutString(
         CxBuffer buffer,
         const char *str
 ) {
     return cxBufferWrite(str, 1, strlen(str), buffer);
 }
 int cxBufferShiftLeft(
         CxBuffer buffer,
         size_t shift
 ) {
     if (shift >= buffer->size) {
         buffer->pos = buffer->size = 0;
     } else {
         memmove(buffer->bytes, buffer->bytes + shift, buffer->size - shift);
         buffer->size -= shift;
         if (buffer->pos >= shift) {
             buffer->pos -= shift;
         } else {
             buffer->pos = 0;
         }
     }
     return 0;
 }
 int cxBufferShiftRight(
         CxBuffer buffer,
         size_t shift
 ) {
     size_t req_capacity = buffer->size + shift;
     size_t movebytes;
     // auto extend buffer, if required and enabled
     if (buffer->capacity < req_capacity) {
         if ((buffer->flags & CX_BUFFER_AUTO_EXTEND) == CX_BUFFER_AUTO_EXTEND) {
             if (cxBufferMinimumCapacity(buffer, req_capacity)) {
                 return 1;
             }
             movebytes = buffer->size;
         } else {
             movebytes = buffer->capacity - shift;
         }
     } else {
         movebytes = buffer->size;
     }
     memmove(buffer->bytes + shift, buffer->bytes, movebytes);
     buffer->size = shift + movebytes;
     buffer->pos += shift;
     if (buffer->pos > buffer->size) {
         buffer->pos = buffer->size;
     }
     return 0;
 }
 int cxBufferShift(
         CxBuffer buffer,
         off_t shift
 ) {
     if (shift < 0) {
         return cxBufferShiftLeft(buffer, (size_t) (-shift));
     } else if (shift > 0) {
         return cxBufferShiftRight(buffer, (size_t) shift);
     } else {
         return 0;
     }
 }

Mercurial > hg > ucx / annotate

src/buffer.c@af6be1e123aa (annotated)

src/buffer.c