Line data    Source code

       1              : /* File: universal_memory_input_stream.c; Copyright and License: see below */
       2              : 
       3              : #include "u8stream/universal_memory_input_stream.h"
       4              : #include "u8stream/universal_input_stream_if.h"
       5              : #include "u8/u8_trace.h"
       6              : #include "u8/u8_log.h"
       7              : #include <string.h>
       8              : #include <assert.h>
       9              : 
      10              : /* the vmt implementing the interface */
      11              : static const universal_input_stream_if_t universal_memory_input_stream_private_if
      12              :     = {
      13              :         .read = (u8_error_t (*)(universal_input_stream_impl_t*, void*, size_t, size_t*)) &universal_memory_input_stream_read,
      14              :         .reset = (u8_error_t (*)(universal_input_stream_impl_t*)) &universal_memory_input_stream_reset
      15              :     };
      16              : 
      17           76 : void universal_memory_input_stream_init ( universal_memory_input_stream_t *this_,
      18              :                                           const void* mem_buf_start,
      19              :                                           size_t mem_buf_size )
      20              : {
      21           76 :     U8_TRACE_BEGIN();
      22           76 :     assert( mem_buf_start != NULL );
      23              : 
      24           76 :     (*this_).mem_buf_start = mem_buf_start;
      25           76 :     (*this_).mem_buf_size = mem_buf_size;
      26           76 :     (*this_).mem_buf_pos = 0;
      27           76 :     universal_input_stream_private_init( &((*this_).input_stream), &universal_memory_input_stream_private_if, this_ );
      28              : 
      29           76 :     U8_TRACE_END();
      30           76 : }
      31              : 
      32           49 : void universal_memory_input_stream_reinit ( universal_memory_input_stream_t *this_,
      33              :                                             const void* mem_buf_start,
      34              :                                             size_t mem_buf_size )
      35              : {
      36           49 :     U8_TRACE_BEGIN();
      37              : 
      38           49 :     universal_memory_input_stream_destroy( this_ );
      39           49 :     universal_memory_input_stream_init( this_, mem_buf_start, mem_buf_size );
      40              : 
      41           49 :     U8_TRACE_END();
      42           49 : }
      43              : 
      44           76 : void universal_memory_input_stream_destroy( universal_memory_input_stream_t *this_ )
      45              : {
      46           76 :     U8_TRACE_BEGIN();
      47              : 
      48           76 :     (*this_).mem_buf_start = NULL;
      49           76 :     (*this_).mem_buf_size = 0;
      50           76 :     (*this_).mem_buf_pos = 0;
      51           76 :     universal_input_stream_private_destroy( &((*this_).input_stream) );
      52              : 
      53           76 :     U8_TRACE_END();
      54           76 : }
      55              : 
      56            4 : u8_error_t universal_memory_input_stream_reset ( universal_memory_input_stream_t *this_ )
      57              : {
      58            4 :     U8_TRACE_BEGIN();
      59            4 :     assert( (*this_).mem_buf_start != NULL );
      60            4 :     const u8_error_t err = U8_ERROR_NONE;
      61              : 
      62            4 :     (*this_).mem_buf_pos = 0;
      63              : 
      64            4 :     U8_TRACE_END_ERR(err);
      65            4 :     return err;
      66              : }
      67              : 
      68          147 : u8_error_t universal_memory_input_stream_read ( universal_memory_input_stream_t *this_, void *out_buffer, size_t max_size, size_t *out_length )
      69              : {
      70              :     /*U8_TRACE_BEGIN();*/
      71          147 :     assert( out_buffer != NULL );
      72          147 :     assert( max_size != 0 );
      73          147 :     assert( out_length != NULL );
      74          147 :     assert( (*this_).mem_buf_start != NULL );
      75          147 :     u8_error_t err = U8_ERROR_NONE;
      76              : 
      77          147 :     const size_t stream_bytes_left = ( (*this_).mem_buf_size - (*this_).mem_buf_pos );
      78          147 :     if ( stream_bytes_left != 0 )
      79              :     {
      80          119 :         const size_t bytes_to_copy = (max_size <= stream_bytes_left) ? max_size : stream_bytes_left;
      81          119 :         char *const buf_first_read = &(  (*(  (char(*)[])(*this_).mem_buf_start  ))[(*this_).mem_buf_pos]  );
      82              : 
      83          119 :         memcpy( out_buffer, buf_first_read, bytes_to_copy );
      84          119 :         (*this_).mem_buf_pos += bytes_to_copy;
      85          119 :         *out_length = bytes_to_copy;
      86              :     }
      87              :     else
      88              :     {
      89           28 :         err = U8_ERROR_END_OF_STREAM;  /* finished, no more bytes to read */
      90           28 :         *out_length = 0;
      91              :     }
      92              : 
      93              :     /*U8_TRACE_END_ERR(err);*/
      94          147 :     return err;
      95              : }
      96              : 
      97           76 : universal_input_stream_t* universal_memory_input_stream_get_input_stream( universal_memory_input_stream_t *this_ )
      98              : {
      99           76 :     U8_TRACE_BEGIN();
     100              : 
     101           76 :     universal_input_stream_t* result = &((*this_).input_stream);
     102              : 
     103           76 :     U8_TRACE_END();
     104           76 :     return result;
     105              : }
     106              : 
     107              : 
     108              : /*
     109              : Copyright 2021-2025 Andreas Warnke
     110              : 
     111              : Licensed under the Apache License, Version 2.0 (the "License");
     112              : you may not use this file except in compliance with the License.
     113              : You may obtain a copy of the License at
     114              : 
     115              :     http://www.apache.org/licenses/LICENSE-2.0
     116              : 
     117              : Unless required by applicable law or agreed to in writing, software
     118              : distributed under the License is distributed on an "AS IS" BASIS,
     119              : WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     120              : See the License for the specific language governing permissions and
     121              : limitations under the License.
     122              : */