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-rw-r--r--src/libmdsserver/mds-message.c219
-rw-r--r--src/libmdsserver/mds-message.h133
2 files changed, 352 insertions, 0 deletions
diff --git a/src/libmdsserver/mds-message.c b/src/libmdsserver/mds-message.c
new file mode 100644
index 0000000..94e9e63
--- /dev/null
+++ b/src/libmdsserver/mds-message.c
@@ -0,0 +1,219 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#include "mds-message.h"
+
+#include <stdlib.h>
+#include <string.h>
+
+
+/**
+ * Initialsie a message slot so that it can
+ * be used by `mds_message_read`.
+ *
+ * @param this Memory slot in which to store the new message
+ * @return Non-zero on error, errno will be set accordingly.
+ * Destroy the message on error.
+ */
+int mds_message_initialise(mds_message_t* this)
+{
+ this->headers = NULL;
+ this->header_count = 0;
+ this->payload = NULL;
+ this->payload_size = 0;
+ this->buffer = NULL;
+ this->buffer_size = 128;
+ this->buffer_ptr = 0;
+ this->buffer = malloc(this->buffer_size * sizeof(char));
+ if (this->buffer == NULL)
+ return -1;
+ return 0;
+}
+
+
+/**
+ * Release all resources in a message, should
+ * be done even if initialisation fails
+ *
+ * @param this The message
+ */
+void mds_message_destroy(mds_message_t* this)
+{
+ if (this->headers != NULL)
+ {
+ size_t i;
+ for (i = 0; i < this->header_count; i++)
+ if (this->headers[i] != NULL)
+ free(this->headers[i]);
+ free(this->headers);
+ }
+
+ if (this->payload != NULL)
+ free(this->payload);
+
+ if (this->buffer != NULL)
+ free(this->buffer);
+}
+
+
+/**
+ * Read the next message from a file descriptor
+ *
+ * @param this Memory slot in which to store the new message
+ * @param fd The file descriptor
+ * @return Non-zero on error, errno will be set accordingly.
+ * Destroy the message on error.
+ */
+int mds_message_read(mds_message_t* this, int fd)
+{
+ return 0;
+}
+
+
+/**
+ * Get the required allocation size for `data` of the
+ * function `mds_message_marshal`
+ *
+ * @param this The message
+ * @param include_buffer Whether buffer should be marshalled (state serialisation, not communication)
+ * @return The size of the message when marshalled
+ */
+size_t mds_message_marshal_size(mds_message_t* this, int include_buffer)
+{
+ size_t rc = (include_buffer ? 3 : 2) + this->header_count + this->payload_size;
+ size_t i;
+ for (i = 0; i < this->header_count; i++)
+ rc += strlen(this->headers[i]);
+ return rc * sizeof(char);
+}
+
+
+/**
+ * Marshal a message, this can be used both when serialising
+ * the servers state or to get the byte stream to send to
+ * the recipient of the message
+ *
+ * @param this The message
+ * @param data Output buffer for the marshalled data
+ * @param include_buffer Whether buffer should be marshalled (state serialisation, not communication)
+ */
+void mds_message_marshal(mds_message_t* this, char* data, int include_buffer)
+{
+ size_t i, n;
+
+ ((size_t*)data)[0] = this->header_count;
+ ((size_t*)data)[1] = this->payload_size;
+ if (include_buffer)
+ ((size_t*)data)[2] = this->buffer_ptr;
+ data += (include_buffer ? 3 : 2) * sizeof(size_t) / sizeof(char);
+
+ for (i = 0; i < this->header_count; i++)
+ {
+ n = strlen(this->headers[i]) + 1;
+ memcpy(data, this->headers[i], n * sizeof(char));
+ data += n;
+ }
+
+ memcpy(data, this->payload, this->payload_size * sizeof(char));
+
+ if (include_buffer)
+ {
+ data += this->payload_size;
+ memcpy(data, this->buffer, this->buffer_ptr * sizeof(char));
+ }
+}
+
+
+/**
+ * Unmarshal a message, it is assumed that the buffer is marshalled
+ *
+ * @param this Memory slot in which to store the new message
+ * @param data In buffer with the marshalled data
+ * @return Non-zero on error, errno will be set accordingly.
+ * Destroy the message on error.
+ */
+int mds_message_unmarshal(mds_message_t* this, char* data)
+{
+ size_t i, n, header_count;
+
+ header_count = ((size_t*)data)[0];
+ this->header_count = 0;
+ this->payload_size = ((size_t*)data)[1];
+ this->buffer_ptr = ((size_t*)data)[2];
+ this->buffer_size = this->buffer_ptr;
+ this->headers = NULL;
+ this->payload = NULL;
+ this->buffer = NULL;
+
+ data += 3 * sizeof(size_t) / sizeof(char);
+
+ /* To 2-power-multiple of 128 bytes. */
+ this->buffer_size >>= 7;
+ if (this->buffer_size == 0)
+ this->buffer_size = 1;
+ else
+ {
+ this->buffer_size -= 1;
+ this->buffer_size |= this->buffer_size >> 1;
+ this->buffer_size |= this->buffer_size >> 2;
+ this->buffer_size |= this->buffer_size >> 4;
+ this->buffer_size |= this->buffer_size >> 8;
+ this->buffer_size |= this->buffer_size >> 16;
+#if __WORDSIZE == 64
+ this->buffer_size |= this->buffer_size >> 32;
+#endif
+ this->buffer_size += 1;
+ }
+ this->buffer_size <<= 7;
+
+ if (header_count > 0)
+ {
+ this->headers = malloc(header_count * sizeof(char*));
+ if (this->headers == NULL)
+ return -1;
+ }
+
+ if (this->payload_size > 0)
+ {
+ this->payload = malloc(this->payload_size * sizeof(char));
+ if (this->payload == NULL)
+ return -1;
+ }
+
+ this->buffer = malloc(this->buffer_size * sizeof(char));
+ if (this->buffer == NULL)
+ return -1;
+
+ for (i = 0; i < this->header_count; i++)
+ {
+ n = strlen(data) + 1;
+ this->headers[i] = malloc(n * sizeof(char));
+ if (this->headers[i] == NULL)
+ return -1;
+ memcpy(this->headers[i], data, n * sizeof(char));
+ data += n;
+ this->header_count++;
+ }
+
+ memcpy(this->payload, data, this->payload_size * sizeof(char));
+ data += this->payload_size;
+
+ memcpy(this->buffer, data, this->buffer_ptr * sizeof(char));
+
+ return 0;
+}
+
diff --git a/src/libmdsserver/mds-message.h b/src/libmdsserver/mds-message.h
new file mode 100644
index 0000000..f04a8c6
--- /dev/null
+++ b/src/libmdsserver/mds-message.h
@@ -0,0 +1,133 @@
+/**
+ * mds — A micro-display server
+ * Copyright © 2014 Mattias Andrée (maandree@member.fsf.org)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+#ifndef MDS_LIBMDSSERVER_MDS_MESSAGE_H
+#define MDS_LIBMDSSERVER_MDS_MESSAGE_H
+
+
+#include <stddef.h>
+
+
+/**
+ * Message passed between a server and a client or between two of either
+ */
+typedef struct mds_message
+{
+ /**
+ * The headers in the message, each element in this list
+ * as an unparsed header, it consists of both the header
+ * name and its associated value, joined by ": ". A header
+ * cannot be `NULL` (unless its memory allocation failed,)
+ * but `headers` itself is NULL if there are not headers.
+ */
+ char** headers;
+
+ /**
+ * The number of headers in the message
+ */
+ size_t header_count;
+
+ /**
+ * The payload of the message, `NULL` if none (of zero-length)
+ */
+ char* payload;
+
+ /**
+ * The size of the payload
+ */
+ size_t payload_size;
+
+ /**
+ * Internal buffer for the reading function
+ */
+ char* buffer;
+
+ /**
+ * The size allocated to `buffer`
+ */
+ size_t buffer_size;
+
+ /**
+ * The number of bytes used in `buffer`
+ */
+ size_t buffer_ptr;
+
+} mds_message_t;
+
+
+/**
+ * Initialsie a message slot so that it can
+ * be used by `mds_message_read`.
+ *
+ * @param this Memory slot in which to store the new message
+ * @return Non-zero on error, errno will be set accordingly.
+ * Destroy the message on error.
+ */
+int mds_message_initialise(mds_message_t* this);
+
+/**
+ * Release all resources in a message, should
+ * be done even if initialisation fails
+ *
+ * @param this The message
+ */
+void mds_message_destroy(mds_message_t* this);
+
+/**
+ * Read the next message from a file descriptor
+ *
+ * @param this Memory slot in which to store the new message
+ * @param fd The file descriptor
+ * @return Non-zero on error, errno will be set accordingly.
+ * Destroy the message on error.
+ */
+int mds_message_read(mds_message_t* this, int fd);
+
+/**
+ * Get the required allocation size for `data` of the
+ * function `mds_message_marshal`
+ *
+ * @param this The message
+ * @param include_buffer Whether buffer should be marshalled (state serialisation, not communication)
+ * @return The size of the message when marshalled
+ */
+size_t mds_message_marshal_size(mds_message_t* this, int include_buffer) __attribute__((pure));
+
+/**
+ * Marshal a message, this can be used both when serialising
+ * the servers state or to get the byte stream to send to
+ * the recipient of the message
+ *
+ * @param this The message
+ * @param data Output buffer for the marshalled data
+ * @param include_buffer Whether buffer should be marshalled (state serialisation, not communication)
+ */
+void mds_message_marshal(mds_message_t* this, char* data, int include_buffer);
+
+/**
+ * Unmarshal a message, it is assumed that the buffer is marshalled
+ *
+ * @param this Memory slot in which to store the new message
+ * @param data In buffer with the marshalled data
+ * @return Non-zero on error, errno will be set accordingly.
+ * Destroy the message on error.
+ */
+int mds_message_unmarshal(mds_message_t* this, char* data);
+
+
+#endif
+
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