added automatically z85 encoding/decoding (again, but this time better)

libpcp/pcpstream.c

@@ -24,10 +24,13 @@
 Pcpstream *ps_init(void) {
   Pcpstream *stream = ucmalloc(sizeof(Pcpstream));
   stream->b = NULL;
+  stream->cache = buffer_new(32, "Pcpstreamcache");
   stream->fd = NULL;
   stream->is_buffer = 0;
   stream->eof = 0;
   stream->err = 0;
+  stream->armor = 0;
+  stream->determine = 0;
   return stream;
 }
 
@@ -46,12 +49,21 @@ Pcpstream *ps_new_inbuffer(Buffer *b) {
 
 Pcpstream *ps_new_outbuffer() {
   Pcpstream *stream = ps_init();
-  stream->b = buffer_new(32, "Pcpstream");
+  stream->b = buffer_new(32, "Pcpstreamoutbuf");
   stream->is_buffer = 1;
   return stream;
 }
 
-size_t ps_read(Pcpstream *stream, void *buf, size_t readbytes) {
+void ps_setdetermine(Pcpstream *stream, size_t blocksize) {
+  stream->determine = 1;
+  stream->blocksize = blocksize;
+}
+
+void ps_armor(Pcpstream *stream) {
+  stream->armor = 1;
+}
+
+size_t ps_read_raw(Pcpstream *stream, void *buf, size_t readbytes) {
   size_t gotbytes = 0;
 
   if(stream->is_buffer) {
@@ -76,10 +88,234 @@ size_t ps_read(Pcpstream *stream, void *buf, size_t readbytes) {
     }
   }
 
+  stream->firstread = 1;
   return gotbytes;
 }
 
+/* return readbytes from cache. if it is more than left in the cache
+   fetch (and decode) the next chunk, append it to cache and return from
+   that */
+size_t ps_read_cached(Pcpstream *stream, void *buf, size_t readbytes) {
+  if(buffer_left(stream->cache) <= readbytes) {
+    /* enough left in current cache */
+    return buffer_get_chunk(stream->cache, buf, readbytes);
+  }
+  else {
+    /* not enough, fetch the next chunk */
+    ps_read_next(stream);
+
+    /* determine overlapping bytes */
+    size_t overlap = readbytes - buffer_left(stream->cache);
+
+    /* fetch the rest from the cache */
+    size_t fromcache = buffer_get_chunk(stream->cache, buf, buffer_left(stream->cache));
+
+    /* fetch the overlap from next, append to buf */
+    if(overlap > buffer_left(stream->next))
+      overlap = buffer_left(stream->next);
+    buffer_get_chunk(stream->next, buf+overlap, overlap);
+
+    /* move the rest of stream->next into cache */
+    buffer_clear(stream->cache);
+    void *rest = buffer_get_remainder(stream->next);
+    buffer_add(stream->cache, rest, buffer_left(stream->next));
+    free(rest);
+
+    /* reset next */
+    buffer_clear(stream->next);
+
+    return fromcache + overlap;
+  }
+}
+
+/* read and decode the next chunk and put it into stream->next */
+size_t ps_read_next(Pcpstream *stream) {
+  if(stream->armor == 1) {
+    /* fetch next chunk and decode it */
+    return ps_read_decode(stream, stream->next, NULL, 0);
+  }
+  else {
+    /* unencoded source, fetch as is */
+    void *buf = ucmalloc(stream->blocksize);
+    size_t got = ps_read_raw(stream, buf, stream->blocksize);
+    buffer_add(stream->next, buf, got);
+    return got;
+  }
+}
+
+size_t ps_read(Pcpstream *stream, void *buf, size_t readbytes) {
+  if(buffer_size(stream->cache) > 0) {
+    /* use cache */
+    return ps_read_cached(stream, buf, readbytes);
+  }
+  else {
+    /* no cache yet */
+    if(stream->determine == 1 && stream->firstread == 0) {
+      /* fetch the first chunk into the cache and decode, if required,
+         recursively call ps_read() again to return the apropriate data */
+      ps_determine(stream);
+      return ps_read(stream, buf, readbytes);
+    }
+    else if(stream->armor == 1) {
+      /* z85 encoding has already been determined, therefore the cache
+	 is now filled, use it then */
+      return ps_read_cached(stream, buf, readbytes);
+    }
+    else {
+      /* read directly from source */
+      return ps_read_raw(stream, buf, readbytes);
+    }
+  }
+}
+
+void ps_determine(Pcpstream *stream) {
+  /* read a raw chunk from source */
+  void *buf = ucmalloc(stream->blocksize);
+  size_t got = ps_read_raw(stream, buf, stream->blocksize);
+
+  /* check if it's binary or not */
+  if(_buffer_is_binary(buf, got) != 0) {
+    /* no, it's armored */
+    stream->armor = 1;
+    ps_read_decode(stream, stream->cache, buf, got);
+  }
+  else {
+    /* just put the raw stuff into the cache */
+    buffer_add(stream->cache, buf, got);
+  }
+}
+
+size_t ps_read_decode(Pcpstream *stream, Buffer *cache, void *buf, size_t bufsize) {
+  size_t zdiff = 1;
+  size_t i = 0;
+  Buffer *z = buffer_new(32, "ztemp");
+
+  if(bufsize > 0) {
+    /* remove newlines, comments and headers, if any */
+    char *z85 = pcp_readz85string(buf, bufsize);
+    buffer_add(z, z85, strlen(z85));
+
+    /* check if we need to read more in order to get a full block */
+    zdiff = stream->blocksize - strlen(z85);
+    i = strlen(z85);
+    free(z85);
+  }
+ 
+  if(zdiff > 0) {
+    /* read in bytewise, ignore newlines and add until the block is full */
+    uint8_t c;
+    while (i < stream->blocksize) {
+      if (ps_read_raw(stream, &c, 1) == 1) {
+	if(c != '\r' && c != '\n') {
+	  buffer_add8(z, c);
+	  i++;
+	}
+      }
+      else
+	break;
+    }
+  }
+
+  /* finally, decode it and put into cache */
+  size_t binlen, outlen;
+  unsigned char *bin = pcp_z85_decode(buffer_get_str(z), &binlen);
+  if(bin == NULL) {
+    /* it's not z85 encoded, so threat it as binary */
+    stream->armor = 1;
+    buffer_add_buf(stream->cache, z);
+    outlen = buffer_size(stream->cache);
+  }
+  else {
+    /* yes, successfully decoded it, put into cache */
+    buffer_add(stream->cache, bin, binlen);
+    outlen = binlen;
+  }
+  
+  buffer_free(z);
+
+  return outlen;
+}
+
 size_t ps_write(Pcpstream *stream, void *buf, size_t writebytes) {
+  Buffer *z = buffer_new(32, "Pcpwritetemp");
+
+  if(stream->armor == 1) {
+    if(buffer_size(stream->cache) + writebytes < stream->blocksize) {
+      /* just put it into the cache and done with it */
+      buffer_add(stream->cache, buf, writebytes);
+    }
+    else {
+      /* z85 encode cache+buf */
+
+      /* check if there's an overlap, if yes, put it aside for the moment */
+      void *aside = NULL;
+      size_t overlap = (buffer_size(stream->cache) + writebytes) - stream->blocksize;
+      if(overlap > 0) {
+	/* yes, store the overlap, put the left part into the cache */
+	aside = ucmalloc(overlap);
+	memcpy(aside, buf + (writebytes - overlap), overlap); /* FIXME: check if this works */
+	buffer_add(stream->cache, buf, writebytes - overlap);
+      }
+      else {
+	/* cache+buf == blocksize */
+	buffer_add(stream->cache, buf, writebytes);
+      }
+
+      /* do z85 0 padding, manually */
+      if(buffer_size(stream->cache) % 4 != 0) {
+	size_t outlen = buffer_size(stream->cache);
+	while (outlen % 4 != 0) 
+	  buffer_add8(stream->cache, 0);
+      }
+
+      size_t zlen, i, pos;    
+      zlen = (buffer_size(stream->cache) * 5 / 4);
+      char *z85 = ucmalloc(zlen);
+
+      zmq_z85_encode(z85, buffer_get(stream->cache), buffer_size(stream->cache));
+
+      pos = stream->linewr;
+      for(i=0; i<zlen; ++i) {
+	if(pos >= 71) {
+	  buffer_add8(z, '\r');
+	  buffer_add8(z, '\n');
+	  pos = 1;
+	}
+	else
+	  pos++;
+	buffer_add8(z, z85[i]);
+      }
+      stream->linewr = pos;
+
+      buffer_clear(stream->cache);
+      if(aside != NULL) {
+	/* there is an overlapping rest, put it into the cache
+	   FIXME: write it on calling ps_close() or ad some ps_finish() function */
+	buffer_add(stream->cache, aside, overlap);
+      }
+    }
+  }
+  else {
+    buffer_add(z, buf, writebytes);
+  }
+
+  if(stream->is_buffer) {
+    buffer_add(stream->b, buffer_get(z), buffer_size(z));
+    writebytes =  buffer_size(z);
+  }
+  else {
+    writebytes = fwrite(buffer_get(z), 1, buffer_size(z), stream->fd);
+    if(ferror(stream->fd) != 0 || writebytes < buffer_size(z)) {
+      stream->err = 1;
+      writebytes = 0;
+    }
+  }
+
+  buffer_free(z);
+  return writebytes;
+}
+
+size_t ps_writeOLD(Pcpstream *stream, void *buf, size_t writebytes) {
   size_t donebytes = 0;
 
   if(stream->is_buffer) {