X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Finput%2Fvcd.c;h=e3c2347ac0875ff6f44f99f000077a691ce3a455;hb=08f8421a9e82;hp=fe9375672d80048e39fb1de6ded1342da45df20a;hpb=d4c937749a92ce6defa2f0095b34692181afe597;p=libsigrok.git

diff --git a/src/input/vcd.c b/src/input/vcd.c
index fe937567..e3c2347a 100644
--- a/src/input/vcd.c
+++ b/src/input/vcd.c
@@ -2,6 +2,7 @@
  * This file is part of the libsigrok project.
  *
  * Copyright (C) 2012 Petteri Aimonen <jpa@sr.mail.kapsi.fi>
+ * Copyright (C) 2014 Bert Vermeulen <bert@biot.com>
  *
  * 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
@@ -25,7 +26,7 @@
  *
  * skip:        Allows skipping until given timestamp in the file.
  *              This can speed up analyzing of long captures.
- *            
+ *
  *              Value < 0: Skip until first timestamp listed in
  *              the file. (default)
  *
@@ -56,26 +57,35 @@
  * - more than 64 channels
  */
 
+#include <config.h>
 #include <stdlib.h>
 #include <glib.h>
 #include <stdio.h>
 #include <string.h>
-#include "libsigrok.h"
+#include <libsigrok/libsigrok.h>
 #include "libsigrok-internal.h"
 
 #define LOG_PREFIX "input/vcd"
 
-#define DEFAULT_NUM_CHANNELS 8
-#define CHUNKSIZE 1024
+#define CHUNK_SIZE (4 * 1024 * 1024)
 
 struct context {
+	gboolean started;
+	gboolean got_header;
+	uint64_t prev_timestamp;
 	uint64_t samplerate;
-	int maxchannels;
-	int channelcount;
+	unsigned int maxchannels;
+	unsigned int channelcount;
 	int downsample;
 	unsigned compress;
 	int64_t skip;
+	gboolean skip_until_end;
 	GSList *channels;
+	size_t bytes_per_sample;
+	size_t samples_in_buffer;
+	uint8_t *buffer;
+	uint8_t *current_levels;
+	GSList *prev_sr_channels;
 };
 
 struct vcd_channel {
@@ -83,99 +93,75 @@ struct vcd_channel {
 	gchar *identifier;
 };
 
-
-/* Read until specific type of character occurs in file.
- * Skip input if dest is NULL.
- * Modes:
- * 'W' read until whitespace
- * 'N' read until non-whitespace, and ungetc() the character
- * '$' read until $end
- */
-static gboolean read_until(FILE *file, GString *dest, char mode)
-{
-	int  c;
-	char prev[4] = "";
-
-	for(;;) {
-		c = fgetc(file);
-
-		if (c == EOF) {
-			if (mode == '$')
-				sr_err("Unexpected EOF.");
-			return FALSE;
-		}
-
-		if (mode == 'W' && g_ascii_isspace(c))
-			return TRUE;
-
-		if (mode == 'N' && !g_ascii_isspace(c)) {
-			ungetc(c, file);
-			return TRUE;
-		}
-
-		if (mode == '$') {
-			prev[0] = prev[1]; prev[1] = prev[2]; prev[2] = prev[3]; prev[3] = c;
-			if (prev[0] == '$' && prev[1] == 'e' && prev[2] == 'n' && prev[3] == 'd') {
-				if (dest != NULL)
-					g_string_truncate(dest, dest->len - 3);
-
-				return TRUE;
-			}
-		}
-
-		if (dest != NULL)
-			g_string_append_c(dest, c);
-	}
-}
-
 /*
- * Reads a single VCD section from input file and parses it to structure.
- * e.g. $timescale 1ps $end  => "timescale" "1ps"
+ * Reads a single VCD section from input file and parses it to name/contents.
+ * e.g. $timescale 1ps $end => "timescale" "1ps"
  */
-static gboolean parse_section(FILE *file, gchar **name, gchar **contents)
+static gboolean parse_section(GString *buf, gchar **name, gchar **contents)
 {
+	GString *sname, *scontent;
 	gboolean status;
-	GString *sname, *scontents;
+	unsigned int pos;
+
+	*name = *contents = NULL;
+	status = FALSE;
+	pos = 0;
+
+	/* Skip UTF8 BOM */
+	if (buf->len >= 3 && !strncmp(buf->str, "\xef\xbb\xbf", 3))
+		pos = 3;
 
-	/* Skip any initial white-space */
-	if (!read_until(file, NULL, 'N')) return FALSE;
+	/* Skip any initial white-space. */
+	while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
+		pos++;
 
 	/* Section tag should start with $. */
-	if (fgetc(file) != '$')
+	if (buf->str[pos++] != '$')
 		return FALSE;
 
-	/* Read the section tag */
 	sname = g_string_sized_new(32);
-	status = read_until(file, sname, 'W');
-
-	/* Skip whitespace before content */
-	status = status && read_until(file, NULL, 'N');
-
-	/* Read the content */
-	scontents = g_string_sized_new(128);
-	status = status && read_until(file, scontents, '$');
-	g_strchomp(scontents->str);
+	scontent = g_string_sized_new(128);
+
+	/* Read the section tag. */
+	while (pos < buf->len && !g_ascii_isspace(buf->str[pos]))
+		g_string_append_c(sname, buf->str[pos++]);
+
+	/* Skip whitespace before content. */
+	while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
+		pos++;
+
+	/* Read the content. */
+	while (pos < buf->len - 4 && strncmp(buf->str + pos, "$end", 4))
+		g_string_append_c(scontent, buf->str[pos++]);
+
+	if (sname->len && pos < buf->len - 4 && !strncmp(buf->str + pos, "$end", 4)) {
+		status = TRUE;
+		pos += 4;
+		while (pos < buf->len && g_ascii_isspace(buf->str[pos]))
+			pos++;
+		g_string_erase(buf, 0, pos);
+	}
 
-	/* Release strings if status is FALSE, return them if status is TRUE */
 	*name = g_string_free(sname, !status);
-	*contents = g_string_free(scontents, !status);
+	*contents = g_string_free(scontent, !status);
+	if (*contents)
+		g_strchomp(*contents);
+
 	return status;
 }
 
 static void free_channel(void *data)
 {
-	struct vcd_channel *vcd_ch = data;
+	struct vcd_channel *vcd_ch;
+
+	vcd_ch = data;
+	if (!vcd_ch)
+		return;
 	g_free(vcd_ch->name);
 	g_free(vcd_ch->identifier);
 	g_free(vcd_ch);
 }
 
-static void release_context(struct context *ctx)
-{
-	g_slist_free_full(ctx->channels, free_channel);
-	g_free(ctx);
-}
-
 /* Remove empty parts from an array returned by g_strsplit. */
 static void remove_empty_parts(gchar **parts)
 {
@@ -190,18 +176,72 @@ static void remove_empty_parts(gchar **parts)
 	*dest = NULL;
 }
 
+/*
+ * Keep track of a previously created channel list, in preparation of
+ * re-reading the input file. Gets called from reset()/cleanup() paths.
+ */
+static void keep_header_for_reread(const struct sr_input *in)
+{
+	struct context *inc;
+
+	inc = in->priv;
+	g_slist_free_full(inc->prev_sr_channels, sr_channel_free_cb);
+	inc->prev_sr_channels = in->sdi->channels;
+	in->sdi->channels = NULL;
+}
+
+/*
+ * Check whether the input file is being re-read, and refuse operation
+ * when essential parameters of the acquisition have changed in ways
+ * that are unexpected to calling applications. Gets called after the
+ * file header got parsed (again).
+ *
+ * Changing the channel list across re-imports of the same file is not
+ * supported, by design and for valid reasons, see bug #1215 for details.
+ * Users are expected to start new sessions when they change these
+ * essential parameters in the acquisition's setup. When we accept the
+ * re-read file, then make sure to keep using the previous channel list,
+ * applications may still reference them.
+ */
+static int check_header_in_reread(const struct sr_input *in)
+{
+	struct context *inc;
+
+	if (!in)
+		return FALSE;
+	inc = in->priv;
+	if (!inc)
+		return FALSE;
+	if (!inc->prev_sr_channels)
+		return TRUE;
+
+	if (sr_channel_lists_differ(inc->prev_sr_channels, in->sdi->channels)) {
+		sr_err("Channel list change not supported for file re-read.");
+		return FALSE;
+	}
+	g_slist_free_full(in->sdi->channels, sr_channel_free_cb);
+	in->sdi->channels = inc->prev_sr_channels;
+	inc->prev_sr_channels = NULL;
+
+	return TRUE;
+}
+
 /*
  * Parse VCD header to get values for context structure.
  * The context structure should be zeroed before calling this.
  */
-static gboolean parse_header(FILE *file, struct context *ctx)
+static gboolean parse_header(const struct sr_input *in, GString *buf)
 {
-	uint64_t p, q;
-	gchar *name = NULL, *contents = NULL;
-	gboolean status = FALSE;
 	struct vcd_channel *vcd_ch;
+	uint64_t p, q;
+	struct context *inc;
+	gboolean status;
+	gchar *name, *contents, **parts;
 
-	while (parse_section(file, &name, &contents)) {
+	inc = in->priv;
+	name = contents = NULL;
+	status = FALSE;
+	while (parse_section(buf, &name, &contents)) {
 		sr_dbg("Section '%s', contents '%s'.", name, contents);
 
 		if (g_strcmp0(name, "enddefinitions") == 0) {
@@ -211,334 +251,486 @@ static gboolean parse_header(FILE *file, struct context *ctx)
 			/*
 			 * The standard allows for values 1, 10 or 100
 			 * and units s, ms, us, ns, ps and fs.
-			 * */
+			 */
 			if (sr_parse_period(contents, &p, &q) == SR_OK) {
-				ctx->samplerate = q / p;
+				inc->samplerate = q / p;
 				if (q % p != 0) {
 					/* Does not happen unless time value is non-standard */
 					sr_warn("Inexact rounding of samplerate, %" PRIu64 " / %" PRIu64 " to %" PRIu64 " Hz.",
-						q, p, ctx->samplerate);
+						q, p, inc->samplerate);
 				}
 
-				sr_dbg("Samplerate: %" PRIu64, ctx->samplerate);
+				sr_dbg("Samplerate: %" PRIu64, inc->samplerate);
 			} else {
 				sr_err("Parsing timescale failed.");
 			}
 		} else if (g_strcmp0(name, "var") == 0) {
-			/* Format: $var type size identifier reference $end */
-			gchar **parts = g_strsplit_set(contents, " \r\n\t", 0);
+			/* Format: $var type size identifier reference [opt. index] $end */
+			unsigned int length;
+
+			parts = g_strsplit_set(contents, " \r\n\t", 0);
 			remove_empty_parts(parts);
+			length = g_strv_length(parts);
 
-			if (g_strv_length(parts) != 4)
-				sr_warn("$var section should have 4 items");
+			if (length != 4 && length != 5)
+				sr_warn("$var section should have 4 or 5 items");
 			else if (g_strcmp0(parts[0], "reg") != 0 && g_strcmp0(parts[0], "wire") != 0)
 				sr_info("Unsupported signal type: '%s'", parts[0]);
 			else if (strtol(parts[1], NULL, 10) != 1)
 				sr_info("Unsupported signal size: '%s'", parts[1]);
-			else if (ctx->channelcount >= ctx->maxchannels)
-				sr_warn("Skipping '%s' because only %d channels requested.", parts[3], ctx->maxchannels);
+			else if (inc->maxchannels && inc->channelcount >= inc->maxchannels)
+				sr_warn("Skipping '%s%s' because only %d channels requested.",
+					parts[3], parts[4] ? : "", inc->maxchannels);
 			else {
-				sr_info("Channel %d is '%s' identified by '%s'.", ctx->channelcount, parts[3], parts[2]);
 				vcd_ch = g_malloc(sizeof(struct vcd_channel));
 				vcd_ch->identifier = g_strdup(parts[2]);
-				vcd_ch->name = g_strdup(parts[3]);
-				ctx->channels = g_slist_append(ctx->channels, vcd_ch);
-				ctx->channelcount++;
+				if (length == 4)
+					vcd_ch->name = g_strdup(parts[3]);
+				else
+					vcd_ch->name = g_strconcat(parts[3], parts[4], NULL);
+
+				sr_info("Channel %d is '%s' identified by '%s'.",
+						inc->channelcount, vcd_ch->name, vcd_ch->identifier);
+
+				sr_channel_new(in->sdi, inc->channelcount++, SR_CHANNEL_LOGIC, TRUE, vcd_ch->name);
+				inc->channels = g_slist_append(inc->channels, vcd_ch);
 			}
 
 			g_strfreev(parts);
 		}
 
-		g_free(name); name = NULL;
-		g_free(contents); contents = NULL;
+		g_free(name);
+		name = NULL;
+		g_free(contents);
+		contents = NULL;
 	}
-
 	g_free(name);
 	g_free(contents);
 
+	/*
+	 * Compute how many bytes each sample will have and initialize the
+	 * current levels. The current levels will be updated whenever VCD
+	 * has changes.
+	 */
+	inc->bytes_per_sample = (inc->channelcount + 7) / 8;
+	inc->current_levels = g_malloc0(inc->bytes_per_sample);
+
+	inc->got_header = status;
+	if (status)
+		status = check_header_in_reread(in);
+
 	return status;
 }
 
-static int format_match(const char *filename)
+static int format_match(GHashTable *metadata, unsigned int *confidence)
 {
-	FILE *file;
-	gchar *name = NULL, *contents = NULL;
+	GString *buf, *tmpbuf;
 	gboolean status;
+	gchar *name, *contents;
 
-	file = fopen(filename, "r");
-	if (file == NULL)
-		return FALSE;
+	buf = g_hash_table_lookup(metadata, GINT_TO_POINTER(SR_INPUT_META_HEADER));
+	tmpbuf = g_string_new_len(buf->str, buf->len);
 
 	/*
 	 * If we can parse the first section correctly,
 	 * then it is assumed to be a VCD file.
 	 */
-	status = parse_section(file, &name, &contents);
-	status = status && (*name != '\0');
-
+	status = parse_section(tmpbuf, &name, &contents);
+	g_string_free(tmpbuf, TRUE);
 	g_free(name);
 	g_free(contents);
-	fclose(file);
 
-	return status;
+	if (!status)
+		return SR_ERR;
+	*confidence = 1;
+
+	return SR_OK;
 }
 
-static int init(struct sr_input *in, const char *filename)
+/* Send all accumulated bytes from inc->buffer. */
+static void send_buffer(const struct sr_input *in)
 {
-	struct sr_channel *ch;
-	int num_channels, i;
-	char name[SR_MAX_CHANNELNAME_LEN + 1];
-	char *param;
-	struct context *ctx;
-
-	(void)filename;
-
-	if (!(ctx = g_try_malloc0(sizeof(*ctx)))) {
-		sr_err("Input format context malloc failed.");
-		return SR_ERR_MALLOC;
-	}
+	struct context *inc;
+	struct sr_datafeed_packet packet;
+	struct sr_datafeed_logic logic;
 
-	num_channels = DEFAULT_NUM_CHANNELS;
-	ctx->samplerate = 0;
-	ctx->downsample = 1;
-	ctx->skip = -1;
-
-	if (in->param) {
-		param = g_hash_table_lookup(in->param, "numchannels");
-		if (param) {
-			num_channels = strtoul(param, NULL, 10);
-			if (num_channels < 1) {
-				release_context(ctx);
-				return SR_ERR;
-			} else if (num_channels > 64) {
-				sr_err("No more than 64 channels supported.");
-				return SR_ERR;
-			}
-		}
+	inc = in->priv;
 
-		param = g_hash_table_lookup(in->param, "downsample");
-		if (param) {
-			ctx->downsample = strtoul(param, NULL, 10);
-			if (ctx->downsample < 1)
-				ctx->downsample = 1;
-		}
+	if (inc->samples_in_buffer == 0)
+		return;
 
-		param = g_hash_table_lookup(in->param, "compress");
-		if (param)
-			ctx->compress = strtoul(param, NULL, 10);
+	packet.type = SR_DF_LOGIC;
+	packet.payload = &logic;
+	logic.unitsize = inc->bytes_per_sample;
+	logic.data = inc->buffer;
+	logic.length = inc->bytes_per_sample * inc->samples_in_buffer;
+	sr_session_send(in->sdi, &packet);
+	inc->samples_in_buffer = 0;
+}
 
-		param = g_hash_table_lookup(in->param, "skip");
-		if (param)
-			ctx->skip = strtoul(param, NULL, 10) / ctx->downsample;
-	}
+/*
+ * Add N copies of the current sample to buffer.
+ * When the buffer fills up, automatically send it.
+ */
+static void add_samples(const struct sr_input *in, size_t count)
+{
+	struct context *inc;
+	size_t samples_per_chunk;
+	size_t space_left, i;
+	uint8_t *p;
 
-	/* Maximum number of channels to parse from the VCD */
-	ctx->maxchannels = num_channels;
+	inc = in->priv;
+	samples_per_chunk = CHUNK_SIZE / inc->bytes_per_sample;
 
-	/* Create a virtual device. */
-	in->sdi = sr_dev_inst_new(0, SR_ST_ACTIVE, NULL, NULL, NULL);
-	in->internal = ctx;
+	while (count) {
+		space_left = samples_per_chunk - inc->samples_in_buffer;
 
-	for (i = 0; i < num_channels; i++) {
-		snprintf(name, SR_MAX_CHANNELNAME_LEN, "%d", i);
+		if (space_left > count)
+			space_left = count;
 
-		if (!(ch = sr_channel_new(i, SR_CHANNEL_LOGIC, TRUE, name))) {
-			release_context(ctx);
-			return SR_ERR;
+		p = inc->buffer + inc->samples_in_buffer * inc->bytes_per_sample;
+		for (i = 0; i < space_left; i++) {
+			memcpy(p, inc->current_levels, inc->bytes_per_sample);
+			p += inc->bytes_per_sample;
+			inc->samples_in_buffer++;
+			count--;
 		}
 
-		in->sdi->channels = g_slist_append(in->sdi->channels, ch);
+		if (inc->samples_in_buffer == samples_per_chunk)
+			send_buffer(in);
 	}
-
-	return SR_OK;
 }
 
-/* Send N samples of the given value. */
-static void send_samples(const struct sr_dev_inst *sdi, uint64_t sample, uint64_t count)
+/* Set the channel level depending on the identifier and parsed value. */
+static void process_bit(struct context *inc, char *identifier, unsigned int bit)
 {
-	struct sr_datafeed_packet packet;
-	struct sr_datafeed_logic logic;
-	uint64_t buffer[CHUNKSIZE];
-	uint64_t i;
-	unsigned chunksize = CHUNKSIZE;
-
-	if (count < chunksize)
-		chunksize = count;
-
-	for (i = 0; i < chunksize; i++)
-		buffer[i] = sample;
-
-	packet.type = SR_DF_LOGIC;
-	packet.payload = &logic;
-	logic.unitsize = sizeof(uint64_t);
-	logic.data = buffer;
-
-	while (count) {
-		if (count < chunksize)
-			chunksize = count;
-
-		logic.length = sizeof(uint64_t) * chunksize;
-
-		sr_session_send(sdi, &packet);
-		count -= chunksize;
+	GSList *l;
+	struct vcd_channel *vcd_ch;
+	unsigned int j;
+
+	for (j = 0, l = inc->channels; j < inc->channelcount && l; j++, l = l->next) {
+		vcd_ch = l->data;
+		if (g_strcmp0(identifier, vcd_ch->identifier) == 0) {
+			/* Found our channel. */
+			size_t byte_idx = (j / 8);
+			size_t bit_idx = j - 8 * byte_idx;
+			if (bit)
+				inc->current_levels[byte_idx] |= (uint8_t)1 << bit_idx;
+			else
+				inc->current_levels[byte_idx] &= ~((uint8_t)1 << bit_idx);
+			break;
+		}
 	}
+	if (j == inc->channelcount)
+		sr_dbg("Did not find channel for identifier '%s'.", identifier);
 }
 
-/* Parse the data section of VCD */
-static void parse_contents(FILE *file, const struct sr_dev_inst *sdi, struct context *ctx)
+/* Parse a set of lines from the data section. */
+static void parse_contents(const struct sr_input *in, char *data)
 {
-	GString *token = g_string_sized_new(32);
+	struct context *inc;
+	uint64_t timestamp;
+	unsigned int bit, i;
+	char **tokens;
 
-	uint64_t prev_timestamp = 0;
-	uint64_t prev_values = 0;
+	inc = in->priv;
 
 	/* Read one space-delimited token at a time. */
-	while (read_until(file, NULL, 'N') && read_until(file, token, 'W')) {
-		if (token->str[0] == '#' && g_ascii_isdigit(token->str[1])) {
+	tokens = g_strsplit_set(data, " \t\r\n", 0);
+	remove_empty_parts(tokens);
+	for (i = 0; tokens[i]; i++) {
+		if (inc->skip_until_end) {
+			if (!strcmp(tokens[i], "$end")) {
+				/* Done with unhandled/unknown section. */
+				inc->skip_until_end = FALSE;
+				break;
+			}
+		}
+		if (tokens[i][0] == '#' && g_ascii_isdigit(tokens[i][1])) {
 			/* Numeric value beginning with # is a new timestamp value */
-			uint64_t timestamp;
-			timestamp = strtoull(token->str + 1, NULL, 10);
+			timestamp = strtoull(tokens[i] + 1, NULL, 10);
 
-			if (ctx->downsample > 1)
-				timestamp /= ctx->downsample;
+			if (inc->downsample > 1)
+				timestamp /= inc->downsample;
 
 			/*
 			 * Skip < 0 => skip until first timestamp.
 			 * Skip = 0 => don't skip
 			 * Skip > 0 => skip until timestamp >= skip.
 			 */
-			if (ctx->skip < 0) {
-				ctx->skip = timestamp;
-				prev_timestamp = timestamp;
-			} else if (ctx->skip > 0 && timestamp < (uint64_t)ctx->skip) {
-				prev_timestamp = ctx->skip;
-			}
-			else if (timestamp == prev_timestamp) {
+			if (inc->skip < 0) {
+				inc->skip = timestamp;
+				inc->prev_timestamp = timestamp;
+			} else if (inc->skip > 0 && timestamp < (uint64_t)inc->skip) {
+				inc->prev_timestamp = inc->skip;
+			} else if (timestamp == inc->prev_timestamp) {
 				/* Ignore repeated timestamps (e.g. sigrok outputs these) */
-			}
-			else {
-				if (ctx->compress != 0 && timestamp - prev_timestamp > ctx->compress)
-				{
+			} else if (timestamp < inc->prev_timestamp) {
+				sr_err("Invalid timestamp: %" PRIu64 " (smaller than previous timestamp).", timestamp);
+				inc->skip_until_end = TRUE;
+				break;
+			} else {
+				if (inc->compress != 0 && timestamp - inc->prev_timestamp > inc->compress) {
 					/* Compress long idle periods */
-					prev_timestamp = timestamp - ctx->compress;
+					inc->prev_timestamp = timestamp - inc->compress;
 				}
 
 				sr_dbg("New timestamp: %" PRIu64, timestamp);
 
 				/* Generate samples from prev_timestamp up to timestamp - 1. */
-				send_samples(sdi, prev_values, timestamp - prev_timestamp);
-				prev_timestamp = timestamp;
+				add_samples(in, timestamp - inc->prev_timestamp);
+				inc->prev_timestamp = timestamp;
 			}
-		} else if (token->str[0] == '$' && token->len > 1) {
-			/* This is probably a $dumpvars, $comment or similar.
-			 * $dump* contain useful data, but other tags will be skipped until $end. */
-			if (g_strcmp0(token->str, "$dumpvars") == 0
-					|| g_strcmp0(token->str, "$dumpon") == 0
-					|| g_strcmp0(token->str, "$dumpoff") == 0
-					|| g_strcmp0(token->str, "$end") == 0) {
+		} else if (tokens[i][0] == '$' && tokens[i][1] != '\0') {
+			/*
+			 * This is probably a $dumpvars, $comment or similar.
+			 * $dump* contain useful data.
+			 */
+			if (g_strcmp0(tokens[i], "$dumpvars") == 0
+					|| g_strcmp0(tokens[i], "$dumpon") == 0
+					|| g_strcmp0(tokens[i], "$dumpoff") == 0
+					|| g_strcmp0(tokens[i], "$end") == 0) {
 				/* Ignore, parse contents as normally. */
 			} else {
-				/* Skip until $end */
-				read_until(file, NULL, '$');
+				/* Ignore this and future lines until $end. */
+				inc->skip_until_end = TRUE;
+				break;
 			}
-		}
-		else if (strchr("bBrR", token->str[0]) != NULL) {
-			/* A vector value. Skip it and also the following identifier. */
-			read_until(file, NULL, 'N');
-			read_until(file, NULL, 'W');
-		} else if (strchr("01xXzZ", token->str[0]) != NULL) {
-			/* A new 1-bit sample value */
-			int i, bit;
-			GSList *l;
-			struct vcd_channel *vcd_ch;
-
-			bit = (token->str[0] == '1');
-
-			g_string_erase(token, 0, 1);
-			if (token->len == 0) {
-				/* There was a space between value and identifier.
-				 * Read in the rest.
-				 */
-				read_until(file, NULL, 'N');
-				read_until(file, token, 'W');
+		} else if (strchr("rR", tokens[i][0]) != NULL) {
+			sr_dbg("Real type vector values not supported yet!");
+			if (!tokens[++i])
+				/* No tokens left, bail out */
+				break;
+			else
+				/* Process next token */
+				continue;
+		} else if (strchr("bB", tokens[i][0]) != NULL) {
+			bit = (tokens[i][1] == '1');
+
+			/*
+			 * Bail out if a) char after 'b' is NUL, or b) there is
+			 * a second character after 'b', or c) there is no
+			 * identifier.
+			 */
+			if (!tokens[i][1] || tokens[i][2] || !tokens[++i]) {
+				sr_dbg("Unexpected vector format!");
+				break;
 			}
 
-			for (i = 0, l = ctx->channels; i < ctx->channelcount && l; i++, l = l->next) {
-				vcd_ch = l->data;
+			process_bit(inc, tokens[i], bit);
+		} else if (strchr("01xXzZ", tokens[i][0]) != NULL) {
+			char *identifier;
 
-				if (g_strcmp0(token->str, vcd_ch->identifier) == 0) {
-					/* Found our channel */
-					if (bit)
-						prev_values |= (uint64_t)1 << i;
-					else
-						prev_values &= ~((uint64_t)1 << i);
+			/* A new 1-bit sample value */
+			bit = (tokens[i][0] == '1');
 
+			/*
+			 * The identifier is either the next character, or, if
+			 * there was whitespace after the bit, the next token.
+			 */
+			if (tokens[i][1] == '\0') {
+				if (!tokens[++i]) {
+					sr_dbg("Identifier missing!");
 					break;
 				}
+				identifier = tokens[i];
+			} else {
+				identifier = tokens[i] + 1;
 			}
-
-			if (i == ctx->channelcount)
-				sr_dbg("Did not find channel for identifier '%s'.", token->str);
+			process_bit(inc, identifier, bit);
 		} else {
-			sr_warn("Skipping unknown token '%s'.", token->str);
+			sr_warn("Skipping unknown token '%s'.", tokens[i]);
 		}
-
-		g_string_truncate(token, 0);
 	}
+	g_strfreev(tokens);
+}
+
+static int init(struct sr_input *in, GHashTable *options)
+{
+	struct context *inc;
+
+	inc = in->priv = g_malloc0(sizeof(struct context));
+
+	inc->maxchannels = g_variant_get_int32(g_hash_table_lookup(options, "numchannels"));
+	inc->downsample = g_variant_get_int32(g_hash_table_lookup(options, "downsample"));
+	if (inc->downsample < 1)
+		inc->downsample = 1;
+
+	inc->compress = g_variant_get_int32(g_hash_table_lookup(options, "compress"));
+	inc->skip = g_variant_get_int32(g_hash_table_lookup(options, "skip"));
+	inc->skip /= inc->downsample;
+
+	in->sdi = g_malloc0(sizeof(struct sr_dev_inst));
+	in->priv = inc;
+
+	inc->buffer = g_malloc(CHUNK_SIZE);
 
-	g_string_free(token, TRUE);
+	return SR_OK;
 }
 
-static int loadfile(struct sr_input *in, const char *filename)
+static gboolean have_header(GString *buf)
+{
+	unsigned int pos;
+	char *p;
+
+	if (!(p = g_strstr_len(buf->str, buf->len, "$enddefinitions")))
+		return FALSE;
+	pos = p - buf->str + 15;
+	while (pos < buf->len - 4 && g_ascii_isspace(buf->str[pos]))
+		pos++;
+	if (!strncmp(buf->str + pos, "$end", 4))
+		return TRUE;
+
+	return FALSE;
+}
+
+static int process_buffer(struct sr_input *in)
 {
 	struct sr_datafeed_packet packet;
 	struct sr_datafeed_meta meta;
 	struct sr_config *src;
-	FILE *file;
-	struct context *ctx;
+	struct context *inc;
 	uint64_t samplerate;
+	char *p;
+
+	inc = in->priv;
+	if (!inc->started) {
+		std_session_send_df_header(in->sdi);
+
+		packet.type = SR_DF_META;
+		packet.payload = &meta;
+		samplerate = inc->samplerate / inc->downsample;
+		src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
+		meta.config = g_slist_append(NULL, src);
+		sr_session_send(in->sdi, &packet);
+		g_slist_free(meta.config);
+		sr_config_free(src);
+
+		inc->started = TRUE;
+	}
 
-	ctx = in->internal;
+	while ((p = g_strrstr_len(in->buf->str, in->buf->len, "\n"))) {
+		*p = '\0';
+		g_strstrip(in->buf->str);
+		if (in->buf->str[0] != '\0')
+			parse_contents(in, in->buf->str);
+		g_string_erase(in->buf, 0, p - in->buf->str + 1);
+	}
 
-	if ((file = fopen(filename, "r")) == NULL)
-		return SR_ERR;
+	return SR_OK;
+}
 
-	if (!parse_header(file, ctx)) {
-		sr_err("VCD parsing failed");
-		fclose(file);
-		return SR_ERR;
+static int receive(struct sr_input *in, GString *buf)
+{
+	struct context *inc;
+	int ret;
+
+	g_string_append_len(in->buf, buf->str, buf->len);
+
+	inc = in->priv;
+	if (!inc->got_header) {
+		if (!have_header(in->buf))
+			return SR_OK;
+		if (!parse_header(in, in->buf))
+			/* There was a header in there, but it was malformed. */
+			return SR_ERR;
+
+		in->sdi_ready = TRUE;
+		/* sdi is ready, notify frontend. */
+		return SR_OK;
 	}
 
-	/* Send header packet to the session bus. */
-	std_session_send_df_header(in->sdi, LOG_PREFIX);
+	ret = process_buffer(in);
 
-	/* Send metadata about the SR_DF_LOGIC packets to come. */
-	packet.type = SR_DF_META;
-	packet.payload = &meta;
-	samplerate = ctx->samplerate / ctx->downsample;
-	src = sr_config_new(SR_CONF_SAMPLERATE, g_variant_new_uint64(samplerate));
-	meta.config = g_slist_append(NULL, src);
-	sr_session_send(in->sdi, &packet);
-	sr_config_free(src);
+	return ret;
+}
+
+static int end(struct sr_input *in)
+{
+	struct context *inc;
+	int ret;
 
-	/* Parse the contents of the VCD file */
-	parse_contents(file, in->sdi, ctx);
+	inc = in->priv;
 
-	/* Send end packet to the session bus. */
-	packet.type = SR_DF_END;
-	sr_session_send(in->sdi, &packet);
+	if (in->sdi_ready)
+		ret = process_buffer(in);
+	else
+		ret = SR_OK;
+
+	/* Send any samples that haven't been sent yet. */
+	send_buffer(in);
 
-	fclose(file);
-	release_context(ctx);
-	in->internal = NULL;
+	if (inc->started)
+		std_session_send_df_end(in->sdi);
+
+	return ret;
+}
+
+static void cleanup(struct sr_input *in)
+{
+	struct context *inc;
+
+	inc = in->priv;
+	keep_header_for_reread(in);
+	g_slist_free_full(inc->channels, free_channel);
+	inc->channels = NULL;
+
+	g_free(inc->buffer);
+	inc->buffer = NULL;
+	g_free(inc->current_levels);
+	inc->current_levels = NULL;
+}
+
+static int reset(struct sr_input *in)
+{
+	struct context *inc = in->priv;
+
+	cleanup(in);
+	g_string_truncate(in->buf, 0);
+
+	inc->started = FALSE;
+	inc->got_header = FALSE;
+	inc->prev_timestamp = 0;
+	inc->skip_until_end = FALSE;
+	inc->channelcount = 0;
+	/* The inc->channels list was released in cleanup() above. */
+	inc->buffer = g_malloc(CHUNK_SIZE);
 
 	return SR_OK;
 }
 
+static struct sr_option options[] = {
+	{ "numchannels", "Number of logic channels", "The number of (logic) channels in the data", NULL, NULL },
+	{ "skip", "Skip samples until timestamp", "Skip samples until the specified timestamp; "
+		"< 0: Skip until first timestamp listed; 0: Don't skip", NULL, NULL },
+	{ "downsample", "Downsampling factor", "Downsample, i.e. divide the samplerate by the specified factor", NULL, NULL },
+	{ "compress", "Compress idle periods", "Compress idle periods longer than the specified value", NULL, NULL },
+	ALL_ZERO
+};
+
+static const struct sr_option *get_options(void)
+{
+	if (!options[0].def) {
+		options[0].def = g_variant_ref_sink(g_variant_new_int32(0));
+		options[1].def = g_variant_ref_sink(g_variant_new_int32(-1));
+		options[2].def = g_variant_ref_sink(g_variant_new_int32(1));
+		options[3].def = g_variant_ref_sink(g_variant_new_int32(0));
+	}
+
+	return options;
+}
+
 SR_PRIV struct sr_input_module input_vcd = {
 	.id = "vcd",
-	.description = "Value Change Dump",
+	.name = "VCD",
+	.desc = "Value Change Dump data",
+	.exts = (const char*[]){"vcd", NULL},
+	.metadata = { SR_INPUT_META_HEADER | SR_INPUT_META_REQUIRED },
+	.options = get_options,
 	.format_match = format_match,
 	.init = init,
-	.loadfile = loadfile,
+	.receive = receive,
+	.end = end,
+	.cleanup = cleanup,
+	.reset = reset,
 };