input/csv: rearrange text to logic data conversion and datafeed

Move the helper routines which arrange for the data feed to an earlier
spot, so that references resolve without forward declarations. Rename
routines to reflect that they deal with logic data.

Slightly unobfuscate column text to logic data conversion, and reduce
redundancy. Move sample data preset to a central location.

Rephrase error messages, provide stronger hints as to why the input text
for a conversion was considered invalid.

Author: gsigh

src/input/csv.c

@@ -174,6 +174,84 @@ struct context {
 	GSList *prev_sr_channels;
 };
 
+/*
+ * Primitive operations to handle sample sets:
+ * - Keep a buffer for datafeed submission, capable of holding many
+ *   samples (reduces call overhead, improves throughput).
+ * - Have a "current sample set" pointer reference one position in that
+ *   large samples buffer.
+ * - Clear the current sample set before text line inspection, then set
+ *   the bits which are found active in the current line of text input.
+ *   Phrase the API such that call sites can be kept simple. Advance to
+ *   the next sample set between lines, flush the larger buffer as needed
+ *   (when it is full, or upon EOF).
+ */
+
+static void clear_logic_samples(struct context *inc)
+{
+	inc->sample_buffer = &inc->datafeed_buffer[inc->datafeed_buf_fill];
+	memset(inc->sample_buffer, 0, inc->sample_unit_size);
+}
+
+static void set_logic_level(struct context *inc, size_t ch_idx, int on)
+{
+	size_t byte_idx, bit_idx;
+	uint8_t bit_mask;
+
+	if (ch_idx >= inc->num_channels)
+		return;
+	if (!on)
+		return;
+
+	byte_idx = ch_idx / 8;
+	bit_idx = ch_idx % 8;
+	bit_mask = 1 << bit_idx;
+	inc->sample_buffer[byte_idx] |= bit_mask;
+}
+
+static int flush_logic_samples(const struct sr_input *in)
+{
+	struct context *inc;
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_logic logic;
+	int rc;
+
+	inc = in->priv;
+	if (!inc->datafeed_buf_fill)
+		return SR_OK;
+
+	memset(&packet, 0, sizeof(packet));
+	memset(&logic, 0, sizeof(logic));
+	packet.type = SR_DF_LOGIC;
+	packet.payload = &logic;
+	logic.unitsize = inc->sample_unit_size;
+	logic.length = inc->datafeed_buf_fill;
+	logic.data = inc->datafeed_buffer;
+
+	rc = sr_session_send(in->sdi, &packet);
+	if (rc != SR_OK)
+		return rc;
+
+	inc->datafeed_buf_fill = 0;
+	return SR_OK;
+}
+
+static int queue_logic_samples(const struct sr_input *in)
+{
+	struct context *inc;
+	int rc;
+
+	inc = in->priv;
+
+	inc->datafeed_buf_fill += inc->sample_unit_size;
+	if (inc->datafeed_buf_fill == inc->datafeed_buf_size) {
+		rc = flush_logic_samples(in);
+		if (rc != SR_OK)
+			return rc;
+	}
+	return SR_OK;
+}
+
 /*
  * Primitive operations for text input: Strip comments off text lines.
  * Split text lines into columns. Process input text for individual
@@ -210,25 +288,22 @@ static void strip_comment(char *buf, const GString *prefix)
 static int parse_binstr(const char *str, struct context *inc)
 {
 	gsize i, j, length;
+	char c;
 
 	length = strlen(str);
-
 	if (!length) {
 		sr_err("Column %zu in line %zu is empty.", inc->single_column,
 			inc->line_number);
 		return SR_ERR;
 	}
 
-	/* Clear buffer in order to set bits only. */
-	memset(inc->sample_buffer, 0, inc->sample_unit_size);
-
 	i = inc->first_channel;
-
 	for (j = 0; i < length && j < inc->num_channels; i++, j++) {
-		if (str[length - i - 1] == '1') {
-			inc->sample_buffer[j / 8] |= (1 << (j % 8));
-		} else if (str[length - i - 1] != '0') {
-			sr_err("Invalid value '%s' in column %zu in line %zu.",
+		c = str[length - i - 1];
+		if (c == '1') {
+			set_logic_level(inc, j, 1);
+		} else if (c != '0') {
+			sr_err("Invalid text '%s' in binary column %zu in line %zu.",
 				str, inc->single_column, inc->line_number);
 			return SR_ERR;
 		}
@@ -256,37 +331,26 @@ static int parse_hexstr(const char *str, struct context *inc)
 	char c;
 
 	length = strlen(str);
-
 	if (!length) {
 		sr_err("Column %zu in line %zu is empty.", inc->single_column,
 			inc->line_number);
 		return SR_ERR;
 	}
 
-	/* Clear buffer in order to set bits only. */
-	memset(inc->sample_buffer, 0, inc->sample_unit_size);
-
 	/* Calculate the position of the first hexadecimal digit. */
 	i = inc->first_channel / 4;
-
 	for (j = 0; i < length && j < inc->num_channels; i++) {
 		c = str[length - i - 1];
-
 		if (!g_ascii_isxdigit(c)) {
-			sr_err("Invalid value '%s' in column %zu in line %zu.",
+			sr_err("Invalid text '%s' in hex column %zu in line %zu.",
 				str, inc->single_column, inc->line_number);
 			return SR_ERR;
 		}
 
 		value = g_ascii_xdigit_value(c);
-
 		k = (inc->first_channel + j) % 4;
-
-		for (; j < inc->num_channels && k < 4; k++) {
-			if (value & (1 << k))
-				inc->sample_buffer[j / 8] |= (1 << (j % 8));
-
-			j++;
+		for (; j < inc->num_channels && k < 4; j++, k++) {
+			set_logic_level(inc, j, value & (1 << k));
 		}
 	}
 
@@ -312,37 +376,26 @@ static int parse_octstr(const char *str, struct context *inc)
 	char c;
 
 	length = strlen(str);
-
 	if (!length) {
 		sr_err("Column %zu in line %zu is empty.", inc->single_column,
 			inc->line_number);
 		return SR_ERR;
 	}
 
-	/* Clear buffer in order to set bits only. */
-	memset(inc->sample_buffer, 0, inc->sample_unit_size);
-
 	/* Calculate the position of the first octal digit. */
 	i = inc->first_channel / 3;
-
 	for (j = 0; i < length && j < inc->num_channels; i++) {
 		c = str[length - i - 1];
-
 		if (c < '0' || c > '7') {
-			sr_err("Invalid value '%s' in column %zu in line %zu.",
+			sr_err("Invalid text '%s' in oct column %zu in line %zu.",
 				str, inc->single_column, inc->line_number);
 			return SR_ERR;
 		}
 
 		value = g_ascii_xdigit_value(c);
-
 		k = (inc->first_channel + j) % 3;
-
-		for (; j < inc->num_channels && k < 3; k++) {
-			if (value & (1 << k))
-				inc->sample_buffer[j / 8] |= (1 << (j % 8));
-
-			j++;
+		for (; j < inc->num_channels && k < 3; j++, k++) {
+			set_logic_level(inc, j, value & (1 << k));
 		}
 	}
 
@@ -441,19 +494,16 @@ static int parse_multi_columns(char **columns, struct context *inc)
 	gsize i;
 	char *column;
 
-	/* Clear buffer in order to set bits only. */
-	memset(inc->sample_buffer, 0, inc->sample_unit_size);
-
 	for (i = 0; i < inc->num_channels; i++) {
 		column = columns[i];
 		if (strcmp(column, "1") == 0) {
-			inc->sample_buffer[i / 8] |= (1 << (i % 8));
+			set_logic_level(inc, i, 1);
 		} else if (!strlen(column)) {
 			sr_err("Column %zu in line %zu is empty.",
 				inc->first_channel + i, inc->line_number);
 			return SR_ERR;
 		} else if (strcmp(column, "0") != 0) {
-			sr_err("Invalid value '%s' in column %zu in line %zu.",
+			sr_err("Invalid text '%s' in bit column %zu in line %zu.",
 				column, inc->first_channel + i,
 				inc->line_number);
 			return SR_ERR;
@@ -463,50 +513,6 @@ static int parse_multi_columns(char **columns, struct context *inc)
 	return SR_OK;
 }
 
-static int flush_samples(const struct sr_input *in)
-{
-	struct context *inc;
-	struct sr_datafeed_packet packet;
-	struct sr_datafeed_logic logic;
-	int rc;
-
-	inc = in->priv;
-	if (!inc->datafeed_buf_fill)
-		return SR_OK;
-
-	memset(&packet, 0, sizeof(packet));
-	memset(&logic, 0, sizeof(logic));
-	packet.type = SR_DF_LOGIC;
-	packet.payload = &logic;
-	logic.unitsize = inc->sample_unit_size;
-	logic.length = inc->datafeed_buf_fill;
-	logic.data = inc->datafeed_buffer;
-
-	rc = sr_session_send(in->sdi, &packet);
-	if (rc != SR_OK)
-		return rc;
-
-	inc->datafeed_buf_fill = 0;
-	return SR_OK;
-}
-
-static int queue_samples(const struct sr_input *in)
-{
-	struct context *inc;
-	int rc;
-
-	inc = in->priv;
-
-	inc->datafeed_buf_fill += inc->sample_unit_size;
-	if (inc->datafeed_buf_fill == inc->datafeed_buf_size) {
-		rc = flush_samples(in);
-		if (rc != SR_OK)
-			return rc;
-	}
-	inc->sample_buffer = &inc->datafeed_buffer[inc->datafeed_buf_fill];
-	return SR_OK;
-}
-
 static int init(struct sr_input *in, GHashTable *options)
 {
 	struct context *inc;
@@ -731,15 +737,14 @@ static int initial_parse(const struct sr_input *in, GString *buf)
 	 * Calculate the minimum buffer size to store the set of samples
 	 * of all channels (unit size). Determine a larger buffer size
 	 * for datafeed submission that is a multiple of the unit size.
-	 * Allocate the larger buffer, and have the "sample buffer" point
-	 * to a location within that large buffer.
+	 * Allocate the larger buffer, the "sample buffer" will point
+	 * to a location within that large buffer later.
 	 */
 	inc->sample_unit_size = (inc->num_channels + 7) / 8;
 	inc->datafeed_buf_size = CHUNK_SIZE;
 	inc->datafeed_buf_size *= inc->sample_unit_size;
 	inc->datafeed_buffer = g_malloc(inc->datafeed_buf_size);
 	inc->datafeed_buf_fill = 0;
-	inc->sample_buffer = &inc->datafeed_buffer[inc->datafeed_buf_fill];
 
 out:
 	if (columns)
@@ -919,6 +924,8 @@ static int process_buffer(struct sr_input *in, gboolean is_eof)
 			return SR_ERR;
 		}
 
+		clear_logic_samples(inc);
+
 		if (inc->multi_column_mode)
 			ret = parse_multi_columns(columns, inc);
 		else
@@ -929,8 +936,8 @@ static int process_buffer(struct sr_input *in, gboolean is_eof)
 			return SR_ERR;
 		}
 
-		/* Send sample data to the session bus. */
-		ret = queue_samples(in);
+		/* Send sample data to the session bus (buffered). */
+		ret = queue_logic_samples(in);
 		if (ret != SR_OK) {
 			sr_err("Sending samples failed.");
 			g_strfreev(columns);
@@ -984,7 +991,7 @@ static int end(struct sr_input *in)
 	if (ret != SR_OK)
 		return ret;
 
-	ret = flush_samples(in);
+	ret = flush_logic_samples(in);
 	if (ret != SR_OK)
 		return ret;